Everybody was wrong!
Thread Starter
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
Everybody was wrong!
And I mean, everybody! The guys at Cylinder Head Exchange, the local machine shop, local Chevy experts, they were wrong and it's not because they were stupid, it's because we went with an off-the-wall combo, that should work, but didn't (at first).
The whole thing started with pulling the greaseball L-48 out of the 74' and finding that, hey, the bottom end is totally clean on this engine. No dash, but the wear and tear on the car, pointed to about 65K to 75K miles. I mean, even the crank bearings were nearly new looking. Cylinders had no scuffing, the pistons only had a micro layer of carbon on top and it burned clean on all cylinders.
Did the research and found out that the early C4 Corvettes, came with aluminum heads off the L98, with the 113 castings being particularly desirable. This is the same style head as on the Chevrolet ZZ4 350 HO motor. They have 58cc combustion chambers and that matched up with the original dished pistons is good for at least a full point of extra compression.
So I got a set, no rocker arms, just the heads, with the old valves and springs and had them rebuilt and everyone I asked, told me they used standard chevy 1.5 rocker arms, because they had pushrod guides in them.
The initial set up ran like crap. The engine spit and popped and we suspected valvetrain set up, so we adjusted them while running. And did it again, finding the rocker arms loose and misaligned. Did it a third time and it went out of adjustment again! Had the Summit cast rocker arms, with the roller tips and swapped them out for a set of standard Sealed Power stamped rocker arms. Also put in a set of pushrods, because the new set got bent.
Initially, we couldn't turn it a half turn, without the engine totally stalling, now it ran better, but still spit and popped, had no power, wouldn't hold vacuum. We called up our race buddy, who's rebuilt dozens and dozens of engines and he told us to check to see if all the rocker arms were the same. Three were slightly different with just a little lower seating in the ball, but that forced us to look closer.
Looking at them, we could see that there were more than a few rocker arms that were so misaligned, they were either nearly off the tip of the valve stem, or actually tilted sideways, or both! Called up the guys at Cylinder Head Exchange and the local machine shop and they swore, that if it had guide plates, you used standard rocker arms. They were wrong.
It took a crap load of digging, but I found out, that the aluminum L98 head is unique. They used a non-hardened guide plate to aid in the engine assembly at the factory, so some worker, could just drop in the push rods, until the self-aligning rocker arms could be put on! I typed in the head casting number #10185086 and found a blog on CarCraft from PontiacMan.
http://forums.carcraft.com/70/891162...ine/sbc-heads/
10185086 Service 10088113 Aluminum Angled No 163 58 1.94/ Service head for Corvette design
Head 150 350 HO, 300 hp. Supplied
with valves & springs.
These ARE the 113 castings you want, but wait... See the note at the bottom:
These Corvette-derived aluminum cylinder heads (PN 10185086) are completely assembled with 1.94/1.50-inch intake/exhaust valves, heavy-duty chrome silicon springs, retainers, screw-in studs, and guide plates. They have 58-cc combustion chambers and the intake runners measure 153 cc. These cylinder heads have angled spark plugs, which may not fit some exhaust manifolds and headers. These heads are plentiful and cheap for those working with a budget.
If you decide to use this cylinder head, you may need to make some additional modifications. Because the exhaust ports exit approximately 0.100 inch higher than the stock, headers and exhaust manifolds may require some minor modifications (and this is why I have a slight exhaust leak as well....). In addition, make sure there is adequate clearance around the angled park plugs. AC FR5LS 3/4-inch reach spark plugs with 5/8-inch hex heads are recommended, and late-model rail type rocker arms are required (PN 10089648).
99% of Chevy heads, come with either guide plates or self-aligned rocker arms, but not both, but these heads come with BOTH and there's a special guide plate, just for these heads! There are two standard guide plates, one for iron heads, one for aluminum, but there's a THIRD guide plate for the L98 head and that's the one that's installed in my head. PN 10111771.
http://www.gmpartsdirect.com/perform...CATID=817.html
Then, from my local Chevy dealer, yesterday, I ordered a set of of the factory, GM Performance rocker arms #12495490, this is the same rocker arm that's used on the ZZ4 and it is self-aligning. I picked them up at lunch and compared them to the regular Chevy rocker arms, and they're a 1/4" shorter!!! No wonder I bent two sets of push rods!
.
So today, I first go to the machine shop to pick up a fresh set of standard length pushrods (my third set...) and the old pro behind the counter swears there's no such thing and everything must be true on the Internet. Again, no such thing as guideplates AND self-aligning rockers.
Go to the GM dealer at 10:30 and pick up my rocker arms. Go directly to the shop, I'm still dressed in business attire, slacks and a polo shirt and start putting assembly lube on the tips of the pushrods and get them in the lifters. Get the paint brush, squeeze some lube and get all the rocker arms, ***** and the top of the pushrods and get them in. It's almost lunch, but I'm on vacation time now. Everything looks exactly lined up, this is good.
We adjust the entire valve train in something like twenty minutes. Put in the backsplash pieces we made out of cardboard. Start the 74' up and no $hit, it's running perfect. No loud tapping, no misalignment, no binding, no loose rocker arms, no tight rocker arms. No spitting, popping, no nothing. Just running smooth and quiet. Unbelievable....! Three weeks of hell getting this right and now we know. I'm gonna make sure the Cylinder Head guys and the machine shop knows too and mail them a copy of what I found. I'm stoked that it's not running like a POS. Tonight, put on the valve covers, drop it down and drive it around and see if it still feels like a 97 pound weakling or is it going to run better? So far, so good.
The whole thing started with pulling the greaseball L-48 out of the 74' and finding that, hey, the bottom end is totally clean on this engine. No dash, but the wear and tear on the car, pointed to about 65K to 75K miles. I mean, even the crank bearings were nearly new looking. Cylinders had no scuffing, the pistons only had a micro layer of carbon on top and it burned clean on all cylinders.
Did the research and found out that the early C4 Corvettes, came with aluminum heads off the L98, with the 113 castings being particularly desirable. This is the same style head as on the Chevrolet ZZ4 350 HO motor. They have 58cc combustion chambers and that matched up with the original dished pistons is good for at least a full point of extra compression.
So I got a set, no rocker arms, just the heads, with the old valves and springs and had them rebuilt and everyone I asked, told me they used standard chevy 1.5 rocker arms, because they had pushrod guides in them.
The initial set up ran like crap. The engine spit and popped and we suspected valvetrain set up, so we adjusted them while running. And did it again, finding the rocker arms loose and misaligned. Did it a third time and it went out of adjustment again! Had the Summit cast rocker arms, with the roller tips and swapped them out for a set of standard Sealed Power stamped rocker arms. Also put in a set of pushrods, because the new set got bent.
Initially, we couldn't turn it a half turn, without the engine totally stalling, now it ran better, but still spit and popped, had no power, wouldn't hold vacuum. We called up our race buddy, who's rebuilt dozens and dozens of engines and he told us to check to see if all the rocker arms were the same. Three were slightly different with just a little lower seating in the ball, but that forced us to look closer.
Looking at them, we could see that there were more than a few rocker arms that were so misaligned, they were either nearly off the tip of the valve stem, or actually tilted sideways, or both! Called up the guys at Cylinder Head Exchange and the local machine shop and they swore, that if it had guide plates, you used standard rocker arms. They were wrong.
It took a crap load of digging, but I found out, that the aluminum L98 head is unique. They used a non-hardened guide plate to aid in the engine assembly at the factory, so some worker, could just drop in the push rods, until the self-aligning rocker arms could be put on! I typed in the head casting number #10185086 and found a blog on CarCraft from PontiacMan.
http://forums.carcraft.com/70/891162...ine/sbc-heads/
10185086 Service 10088113 Aluminum Angled No 163 58 1.94/ Service head for Corvette design
Head 150 350 HO, 300 hp. Supplied
with valves & springs.
These ARE the 113 castings you want, but wait... See the note at the bottom:
These Corvette-derived aluminum cylinder heads (PN 10185086) are completely assembled with 1.94/1.50-inch intake/exhaust valves, heavy-duty chrome silicon springs, retainers, screw-in studs, and guide plates. They have 58-cc combustion chambers and the intake runners measure 153 cc. These cylinder heads have angled spark plugs, which may not fit some exhaust manifolds and headers. These heads are plentiful and cheap for those working with a budget.
If you decide to use this cylinder head, you may need to make some additional modifications. Because the exhaust ports exit approximately 0.100 inch higher than the stock, headers and exhaust manifolds may require some minor modifications (and this is why I have a slight exhaust leak as well....). In addition, make sure there is adequate clearance around the angled park plugs. AC FR5LS 3/4-inch reach spark plugs with 5/8-inch hex heads are recommended, and late-model rail type rocker arms are required (PN 10089648).
99% of Chevy heads, come with either guide plates or self-aligned rocker arms, but not both, but these heads come with BOTH and there's a special guide plate, just for these heads! There are two standard guide plates, one for iron heads, one for aluminum, but there's a THIRD guide plate for the L98 head and that's the one that's installed in my head. PN 10111771.
http://www.gmpartsdirect.com/perform...CATID=817.html
Then, from my local Chevy dealer, yesterday, I ordered a set of of the factory, GM Performance rocker arms #12495490, this is the same rocker arm that's used on the ZZ4 and it is self-aligning. I picked them up at lunch and compared them to the regular Chevy rocker arms, and they're a 1/4" shorter!!! No wonder I bent two sets of push rods!
.So today, I first go to the machine shop to pick up a fresh set of standard length pushrods (my third set...) and the old pro behind the counter swears there's no such thing and everything must be true on the Internet. Again, no such thing as guideplates AND self-aligning rockers.
Go to the GM dealer at 10:30 and pick up my rocker arms. Go directly to the shop, I'm still dressed in business attire, slacks and a polo shirt and start putting assembly lube on the tips of the pushrods and get them in the lifters. Get the paint brush, squeeze some lube and get all the rocker arms, ***** and the top of the pushrods and get them in. It's almost lunch, but I'm on vacation time now. Everything looks exactly lined up, this is good.
We adjust the entire valve train in something like twenty minutes. Put in the backsplash pieces we made out of cardboard. Start the 74' up and no $hit, it's running perfect. No loud tapping, no misalignment, no binding, no loose rocker arms, no tight rocker arms. No spitting, popping, no nothing. Just running smooth and quiet. Unbelievable....! Three weeks of hell getting this right and now we know. I'm gonna make sure the Cylinder Head guys and the machine shop knows too and mail them a copy of what I found. I'm stoked that it's not running like a POS. Tonight, put on the valve covers, drop it down and drive it around and see if it still feels like a 97 pound weakling or is it going to run better? So far, so good.
Race Director
Joined: Feb 2006
Posts: 12,239
Likes: 19
From: Chino CA
And I mean, everybody! The guys at Cylinder Head Exchange, the local machine shop, local Chevy experts, they were wrong and it's not because they were stupid, it's because we went with an off-the-wall combo, that should work, but didn't (at first).
The whole thing started with pulling the greaseball L-48 out of the 74' and finding that, hey, the bottom end is totally clean on this engine. No dash, but the wear and tear on the car, pointed to about 65K to 75K miles. I mean, even the crank bearings were nearly new looking. Cylinders had no scuffing, the pistons only had a micro layer of carbon on top and it burned clean on all cylinders.
Did the research and found out that the early C4 Corvettes, came with aluminum heads off the L98, with the 113 castings being particularly desirable. This is the same style head as on the Chevrolet ZZ4 350 HO motor. They have 58cc combustion chambers and that matched up with the original dished pistons is good for at least a full point of extra compression.
So I got a set, no rocker arms, just the heads, with the old valves and springs and had them rebuilt and everyone I asked, told me they used standard chevy 1.5 rocker arms, because they had pushrod guides in them.
The initial set up ran like crap. The engine spit and popped and we suspected valvetrain set up, so we adjusted them while running. And did it again, finding the rocker arms loose and misaligned. Did it a third time and it went out of adjustment again! Had the Summit cast rocker arms, with the roller tips and swapped them out for a set of standard Sealed Power stamped rocker arms. Also put in a set of pushrods, because the new set got bent.
Initially, we couldn't turn it a half turn, without the engine totally stalling, now it ran better, but still spit and popped, had no power, wouldn't hold vacuum. We called up our race buddy, who's rebuilt dozens and dozens of engines and he told us to check to see if all the rocker arms were the same. Three were slightly different with just a little lower seating in the ball, but that forced us to look closer.
Looking at them, we could see that there were more than a few rocker arms that were so misaligned, they were either nearly off the tip of the valve stem, or actually tilted sideways, or both! Called up the guys at Cylinder Head Exchange and the local machine shop and they swore, that if it had guide plates, you used standard rocker arms. They were wrong.
It took a crap load of digging, but I found out, that the aluminum L98 head is unique. They used a non-hardened guide plate to aid in the engine assembly at the factory, so some worker, could just drop in the push rods, until the self-aligning rocker arms could be put on! I typed in the head casting number #10185086 and found a blog on CarCraft from PontiacMan.
http://forums.carcraft.com/70/891162...ine/sbc-heads/
10185086 Service 10088113 Aluminum Angled No 163 58 1.94/ Service head for Corvette design
Head 150 350 HO, 300 hp. Supplied
with valves & springs.
These ARE the 113 castings you want, but wait... See the note at the bottom:
These Corvette-derived aluminum cylinder heads (PN 10185086) are completely assembled with 1.94/1.50-inch intake/exhaust valves, heavy-duty chrome silicon springs, retainers, screw-in studs, and guide plates. They have 58-cc combustion chambers and the intake runners measure 153 cc. These cylinder heads have angled spark plugs, which may not fit some exhaust manifolds and headers. These heads are plentiful and cheap for those working with a budget.
If you decide to use this cylinder head, you may need to make some additional modifications. Because the exhaust ports exit approximately 0.100 inch higher than the stock, headers and exhaust manifolds may require some minor modifications (and this is why I have a slight exhaust leak as well....). In addition, make sure there is adequate clearance around the angled park plugs. AC FR5LS 3/4-inch reach spark plugs with 5/8-inch hex heads are recommended, and late-model rail type rocker arms are required (PN 10089648).
99% of Chevy heads, come with either guide plates or self-aligned rocker arms, but not both, but these heads come with BOTH and there's a special guide plate, just for these heads! There are two standard guide plates, one for iron heads, one for aluminum, but there's a THIRD guide plate for the L98 head and that's the one that's installed in my head. PN 10111771.
http://www.gmpartsdirect.com/perform...CATID=817.html
Then, from my local Chevy dealer, yesterday, I ordered a set of of the factory, GM Performance rocker arms #12495490, this is the same rocker arm that's used on the ZZ4 and it is self-aligning. I picked them up at lunch and compared them to the regular Chevy rocker arms, and they're a 1/4" shorter!!! No wonder I bent two sets of push rods!.
So today, I first go to the machine shop to pick up a fresh set of standard length pushrods (my third set...) and the old pro behind the counter swears there's no such thing and everything must be true on the Internet. Again, no such thing as guideplates AND self-aligning rockers.
Go to the GM dealer at 10:30 and pick up my rocker arms. Go directly to the shop, I'm still dressed in business attire, slacks and a polo shirt and start putting assembly lube on the tips of the pushrods and get them in the lifters. Get the paint brush, squeeze some lube and get all the rocker arms, ***** and the top of the pushrods and get them in. It's almost lunch, but I'm on vacation time now. Everything looks exactly lined up, this is good.
We adjust the entire valve train in something like twenty minutes. Put in the backsplash pieces we made out of cardboard. Start the 74' up and no $hit, it's running perfect. No loud tapping, no misalignment, no binding, no loose rocker arms, no tight rocker arms. No spitting, popping, no nothing. Just running smooth and quiet. Unbelievable....! Three weeks of hell getting this right and now we know. I'm gonna make sure the Cylinder Head guys and the machine shop knows too and mail them a copy of what I found. I'm stoked that it's not running like a POS. Tonight, put on the valve covers, drop it down and drive it around and see if it still feels like a 97 pound weakling or is it going to run better? So far, so good.
The whole thing started with pulling the greaseball L-48 out of the 74' and finding that, hey, the bottom end is totally clean on this engine. No dash, but the wear and tear on the car, pointed to about 65K to 75K miles. I mean, even the crank bearings were nearly new looking. Cylinders had no scuffing, the pistons only had a micro layer of carbon on top and it burned clean on all cylinders.
Did the research and found out that the early C4 Corvettes, came with aluminum heads off the L98, with the 113 castings being particularly desirable. This is the same style head as on the Chevrolet ZZ4 350 HO motor. They have 58cc combustion chambers and that matched up with the original dished pistons is good for at least a full point of extra compression.
So I got a set, no rocker arms, just the heads, with the old valves and springs and had them rebuilt and everyone I asked, told me they used standard chevy 1.5 rocker arms, because they had pushrod guides in them.
The initial set up ran like crap. The engine spit and popped and we suspected valvetrain set up, so we adjusted them while running. And did it again, finding the rocker arms loose and misaligned. Did it a third time and it went out of adjustment again! Had the Summit cast rocker arms, with the roller tips and swapped them out for a set of standard Sealed Power stamped rocker arms. Also put in a set of pushrods, because the new set got bent.
Initially, we couldn't turn it a half turn, without the engine totally stalling, now it ran better, but still spit and popped, had no power, wouldn't hold vacuum. We called up our race buddy, who's rebuilt dozens and dozens of engines and he told us to check to see if all the rocker arms were the same. Three were slightly different with just a little lower seating in the ball, but that forced us to look closer.
Looking at them, we could see that there were more than a few rocker arms that were so misaligned, they were either nearly off the tip of the valve stem, or actually tilted sideways, or both! Called up the guys at Cylinder Head Exchange and the local machine shop and they swore, that if it had guide plates, you used standard rocker arms. They were wrong.
It took a crap load of digging, but I found out, that the aluminum L98 head is unique. They used a non-hardened guide plate to aid in the engine assembly at the factory, so some worker, could just drop in the push rods, until the self-aligning rocker arms could be put on! I typed in the head casting number #10185086 and found a blog on CarCraft from PontiacMan.
http://forums.carcraft.com/70/891162...ine/sbc-heads/
10185086 Service 10088113 Aluminum Angled No 163 58 1.94/ Service head for Corvette design
Head 150 350 HO, 300 hp. Supplied
with valves & springs.
These ARE the 113 castings you want, but wait... See the note at the bottom:
These Corvette-derived aluminum cylinder heads (PN 10185086) are completely assembled with 1.94/1.50-inch intake/exhaust valves, heavy-duty chrome silicon springs, retainers, screw-in studs, and guide plates. They have 58-cc combustion chambers and the intake runners measure 153 cc. These cylinder heads have angled spark plugs, which may not fit some exhaust manifolds and headers. These heads are plentiful and cheap for those working with a budget.
If you decide to use this cylinder head, you may need to make some additional modifications. Because the exhaust ports exit approximately 0.100 inch higher than the stock, headers and exhaust manifolds may require some minor modifications (and this is why I have a slight exhaust leak as well....). In addition, make sure there is adequate clearance around the angled park plugs. AC FR5LS 3/4-inch reach spark plugs with 5/8-inch hex heads are recommended, and late-model rail type rocker arms are required (PN 10089648).
99% of Chevy heads, come with either guide plates or self-aligned rocker arms, but not both, but these heads come with BOTH and there's a special guide plate, just for these heads! There are two standard guide plates, one for iron heads, one for aluminum, but there's a THIRD guide plate for the L98 head and that's the one that's installed in my head. PN 10111771.
http://www.gmpartsdirect.com/perform...CATID=817.html
Then, from my local Chevy dealer, yesterday, I ordered a set of of the factory, GM Performance rocker arms #12495490, this is the same rocker arm that's used on the ZZ4 and it is self-aligning. I picked them up at lunch and compared them to the regular Chevy rocker arms, and they're a 1/4" shorter!!! No wonder I bent two sets of push rods!
.So today, I first go to the machine shop to pick up a fresh set of standard length pushrods (my third set...) and the old pro behind the counter swears there's no such thing and everything must be true on the Internet. Again, no such thing as guideplates AND self-aligning rockers.
Go to the GM dealer at 10:30 and pick up my rocker arms. Go directly to the shop, I'm still dressed in business attire, slacks and a polo shirt and start putting assembly lube on the tips of the pushrods and get them in the lifters. Get the paint brush, squeeze some lube and get all the rocker arms, ***** and the top of the pushrods and get them in. It's almost lunch, but I'm on vacation time now. Everything looks exactly lined up, this is good.
We adjust the entire valve train in something like twenty minutes. Put in the backsplash pieces we made out of cardboard. Start the 74' up and no $hit, it's running perfect. No loud tapping, no misalignment, no binding, no loose rocker arms, no tight rocker arms. No spitting, popping, no nothing. Just running smooth and quiet. Unbelievable....! Three weeks of hell getting this right and now we know. I'm gonna make sure the Cylinder Head guys and the machine shop knows too and mail them a copy of what I found. I'm stoked that it's not running like a POS. Tonight, put on the valve covers, drop it down and drive it around and see if it still feels like a 97 pound weakling or is it going to run better? So far, so good.
Get 'er done before the cruise !
Drifting
Joined: Aug 2005
Posts: 1,443
Likes: 65
From: Wauconda IL
The self-aligning rockers and guide plates on the L-98 has been well documented in any write-up I've read regarding these heads.
Worst case, always refer to GM's own documentation vs listening to some Bubba at the machine shop to avoid any issues.
I do find it odd that you couldn't get standard rockers and hardened guide plates to work as the valve position on these heads are no different than any standard SBC head. Did you actually measure for proper length pushrods or just stick in standard length ones and hope for the best? With all the pushrod bending you had going on, pushrod length with proper guide plates would have been my first place to check.
Just my .02
Worst case, always refer to GM's own documentation vs listening to some Bubba at the machine shop to avoid any issues.
I do find it odd that you couldn't get standard rockers and hardened guide plates to work as the valve position on these heads are no different than any standard SBC head. Did you actually measure for proper length pushrods or just stick in standard length ones and hope for the best? With all the pushrod bending you had going on, pushrod length with proper guide plates would have been my first place to check.
Just my .02
Last edited by ezobens; Apr 9, 2013 at 07:25 PM.
Thread Starter
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
The self-aligning rockers and guide plates on the L-98 has been well documented in any write-up I've read regarding these heads.
Worst case, always refer to GM's own documentation vs listening to some Bubba at the machine shop to avoid any issues.
I do find it odd that you couldn't get standard rockers and hardened guide plates to work as the valve position on these heads are no different than any standard SBC head. Did you actually measure for proper length pushrods or just stick in standard length ones and hope for the best? With all the pushrod bending you had going on, pushrod length with proper guide plates would have been my first place to check.
Just my .02
Worst case, always refer to GM's own documentation vs listening to some Bubba at the machine shop to avoid any issues.
I do find it odd that you couldn't get standard rockers and hardened guide plates to work as the valve position on these heads are no different than any standard SBC head. Did you actually measure for proper length pushrods or just stick in standard length ones and hope for the best? With all the pushrod bending you had going on, pushrod length with proper guide plates would have been my first place to check.
Just my .02
Melting Slicks
Joined: Jan 2003
Posts: 3,027
Likes: 94
From: meraux LA
Don't know why you had problems. I put a set of these heads on a gm crate motor short block, a few years ago. when I got my heads they were complete with the self-aligning rockers all I had to do was measure for the push rods. No problems in over 4 years.
Thread Starter
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
Took two hours off to install the valve train and then left an hour early to boot! We started it, no noise, tweaked it and backed it out of the shop into a nearly deserted industrial center. Rolling back, healthy idle, crisp throttle response, so what's it gonna do?
Put the stick in first gear, stabbed it and dropped the clutch. The engine snarled, tires broke loose and the *** end came around. Grabbed second and the back end squatted hard. OMG!!! Every expectation was exceeded! RPM's rising hard and the nose still coming up. Stoked, stoked, stoked. This thing would slay my 95' C4....After three weeks, three valvetrains and nights at the shop, we're rewarded.
Put the stick in first gear, stabbed it and dropped the clutch. The engine snarled, tires broke loose and the *** end came around. Grabbed second and the back end squatted hard. OMG!!! Every expectation was exceeded! RPM's rising hard and the nose still coming up. Stoked, stoked, stoked. This thing would slay my 95' C4....After three weeks, three valvetrains and nights at the shop, we're rewarded.
Last edited by F22; Apr 9, 2013 at 11:09 PM.
Thread Starter
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
Didn!t come with the rockers, as I planned on new rockers anyways. If you dontknow, ya don't know and glad to hear your combo works well, good to know. Most people are just skipping the L98 heads and just going with the AFR's, etc.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
7 Bolt-On Upgrades From Extreme Online Store to Level Up Your C6 Corvette
Pouria Savadkouei
Melting Slicks
Joined: Aug 2012
Posts: 2,548
Likes: 379
From: Woodinville WA
I ran those heads with no trouble either.... used roller tip rocker arms... weird, sounds like I got lucky... (which, if I had a choice, I'll take lucky over good every time)
Thread Starter
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
PS: Did my best to research this, beforehand. Even purchased "The Chevy Small Block Interchange Manual, by David Lewis, The L98 heads are coverd, but no mention of the DUAL use of inert guide plates AND self-aligning rockers, but yet it was helpful, because they showed in another pic, the two style rocker arms, early (standard) and the now common place, self aligning rocker arm. The author stated they started using these in the mid-80's.... Hmmm.
That tickled the memory cells kicked in. I had done the top-end on my third ex-wife's 87' Corvette and I didn't remember seeing hard contact between the rocker arms and the guides. The next day, went on my Photobucket account, where I still had hundreds of photos of the process and sure enough, tbey were self-aligning. Fixed! And even online, it took a lot of searches. I'm posting this, so somebody who does this, doesn't have to go through the same experience I did.
That tickled the memory cells kicked in. I had done the top-end on my third ex-wife's 87' Corvette and I didn't remember seeing hard contact between the rocker arms and the guides. The next day, went on my Photobucket account, where I still had hundreds of photos of the process and sure enough, tbey were self-aligning. Fixed! And even online, it took a lot of searches. I'm posting this, so somebody who does this, doesn't have to go through the same experience I did.
Last edited by F22; Apr 9, 2013 at 11:40 PM.
Safety Car
Joined: Jan 2009
Posts: 3,873
Likes: 25
Well written. Theres few that can keep my attenion for long. But I noticed that I read the whole thing, and didn't even blink. Well done..... Also..........I once bent and broke a bunch on our pontiac the same way. So better put an old speaker magnet on the side of your oil pan to catch the particles. After that, I also glued some on the oil drain backs before it can even get to the pan. ......... Now go smoke the tires w/video..................
Also..........I once bent and broke a bunch on our pontiac the same way. So better put an old speaker magnet on the side of your oil pan to catch the particles. After that, I also glued some on the oil drain backs before it can even get to the pan. ......... Now go smoke the tires w/video..................
Thread Starter
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
Well written. Theres few that can keep my attenion for long. But I noticed that I read the whole thing, and didn't even blink. Well done..... Also..........I once bent and broke a bunch on our pontiac the same way. So better put an old speaker magnet on the side of your oil pan to catch the particles. After that, I also glued some on the oil drain backs before it can even get to the pan. ......... Now go smoke the tires w/video..................
Also..........I once bent and broke a bunch on our pontiac the same way. So better put an old speaker magnet on the side of your oil pan to catch the particles. After that, I also glued some on the oil drain backs before it can even get to the pan. ......... Now go smoke the tires w/video..................A coworker of mine, good bud races the NMRA series with a six second 92' Camaro and I asked him if he threw hundreds of dollars at stuff that didn't work and that he never used again and he immediately agreed and summed it up, saying it can be "hit and miss". I didn't feel so bad after that. Thank you all and this is why I love this forum!
Last edited by F22; Apr 10, 2013 at 01:43 AM.
Thread Starter
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
PPS. The Lunati Voodoo cam is a 272 grind, for RV's, 4x4's and Marine applications, or where bottom end torque counts. I had reservations about the cam Lunati recommended for a daily driver, wanting to go with the 268, higher lift cam, like many others. Top end is nice, but that hard pull and torque is good for some giggles too!
1st Gear
Joined: Dec 2020
Posts: 1
Likes: 0
I have these heads on a ZZ1 HO 350. I’m looking for replacement rocker studs. I’m having trouble finding adequate technical assistance from GM. Does anyone have a suggestion for a dealer with direct knowledge of these heads?
Thanks
Thanks