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Hello good people of Corvette Forum!
I have a 79 L82 4sp w 70k miles. Bone stock. So I am upgrading the engine so it runs and sounds like a real Corvette.
I would love everyone's thoughts on this set up. Specifically am I OK on hood clearance?
AFR 195/64cc heads
Edelbrock Performer RPM intake
PRW 1.6rockers w 7.75 pushrods
Doug's D334b headers
Stock L82 cam
Going to rebuild the Q Jet carb.
Will run through 2.5 exhaust and Flowmasters.
Are the springs in the AFR heads too stiff for the flat tappet cam?
Anything else to look out for? Drone from the Flowmasters?
I went with Edelbrock heads on my L82 but if I had to do it again, I would probably go with AFR heads.
The cam should be fine with the springs, I would probably replace the lifters and use plenty of moly lube. Smart to keep the Qjet.
Plenty of more experienced builders than me here so they may suggest otherwise.
Will it fit? Yes it should, I ran a very similar set-up for many years on my 77.
Here's the thing thou, the drivers side motor mount on manual cars is notorious for letting go. When it does and you launch it hard. . . .
Well, I ended up with a nice star crack in my original hood.
I highly recommend you concider Moroso solid mounts. I got tired of replacing stock type motor mounts.
And I know everyone on here will say keep the quadrapuke!
I put on a Holley with the correct RPM manifold.
Your changing the exhaust, the heads, the compression, even the cam by going 1.6-1 rockers. You will need to tune that quadrajunk. Tuning parts are as rare as rocking horse ****. And people that know how to tune them properly are also rare. So, rebuilding it yourself won't get it close. Send it to Lars. Or put something on people can tune.
And yes I believe that is really good advice.
You'll want to recurve that distributor as well.
And why are you putting mufflers on it? I thought you wanted it to sound like a Corvette!
Haven't had a muffler on mine since the 80's!
Have fun!
I rebuilt/upgraded my stock L-82 engine 4 speed with 66,000 miles in 2014 with a complete bottom end refresh, reconditioning many of the L-82 OEM components like the L-82 rods, L-82 forged crank, etc. with new JE forged Racing pistons, new rod bearings, new oil pump, etc. Based on my research and talking with many experienced forum members along with my local GM Chevy expert builder in my area, I went with AFR's (strongly recommend their heads) BUT the 180 64 CC, not the 195's, despite the 195's flowing slightly more CFM at higher RPM's (where my engine rarely would be), but will be more sluggish than the 180's in the low RPM range, with the 180's having much stronger mid range torque. My experience now 11 years years on with the AFR's is spot on with this assessment.
As noted on previous posts recently, the L-82 cam with some compression is actually pretty impressive for a flat tappet cam and will be even better with 1.6 ratio rockers. My OEM L-82 was running comp cams 1.5 roller tipped rockers at the time of the upgrade which I reused on the rebuilt L-82 355. If you do want to replace the OEM L-82 cam, I would highly recommend my Howard Roller Retrofit cam with .525 Lift/LSA 110/duration 219/225 versus the L-82 cams .450/.460 lift/Duration 222/LSA 114 with the roller cam just making more power everywhere in the power curve versus a flat tappet cam, even with similar specs.
As for the intake and carb choice, the Edelbrock RPM is a good choice BUT will not fit the L-82 OEM dual snorkel cold air cleaner intake system (you will need a drop base open air cleaner), if you plan on keeping the OEM setup and look, like I have and did. I reused the OEM aluminum L-82 intake manifold, mildly ported by my engine expert friend, retaining as much L-82, as possible within reason, considering this 78 C3 is confined to street driving with occasional high rpm blasts. I wasn't looking for maximum HP/TQ everywhere but ended up with serious HP/TQ, even with a few compromises, like the L-82 intake . If I would change my intake manifold, I would consider also the GM SBC ZZ4 intake since in most test I read it produces the most power, very similar to the OEM LT-1 intake BUT 1/2 inch shorter. If you have the OEM L-82 Quadrajet send it to LARS for a rebuild/tune, but definitely keep it, even if you use a different carb. I did not have my original Qjet and have been using a Holley 4175 650 CFM vacuum secondary spreadbore (which is designed to be a direct replacement for the Qjet) for 40 years with tremendous success on both the OEM L-82 and the L-82 355 with some minor easy tuning.
I run 1 7/8 inch LTHeaders through 2.5 inch duals to C4 corvette Borla Type S SS mufflers, custom fit to a C3......pretty much optimized exhaust for my setup with an incredible unmatched sound, IMO, for a SBC Corvette....no motorboat sounding exhaust or drone but more of a tuned SBC V8 sound...very unique.
Will it fit? Yes it should, I ran a very similar set-up for many years on my 77.
Here's the thing thou, the drivers side motor mount on manual cars is notorious for letting go. When it does and you launch it hard. . . .
Well, I ended up with a nice star crack in my original hood.
I highly recommend you concider Moroso solid mounts. I got tired of replacing stock type motor mounts.
And I know everyone on here will say keep the quadrapuke!
I put on a Holley with the correct RPM manifold.
Your changing the exhaust, the heads, the compression, even the cam by going 1.6-1 rockers. You will need to tune that quadrajunk. Tuning parts are as rare as rocking horse ****. And people that know how to tune them properly are also rare. So, rebuilding it yourself won't get it close. Send it to Lars. Or put something on people can tune.
And yes I believe that is really good advice.
You'll want to recurve that distributor as well.
And why are you putting mufflers on it? I thought you wanted it to sound like a Corvette!
Haven't had a muffler on mine since the 80's!
Have fun!
Rare as rocking horse ****! 😂 I'm 100% stealing that! And thanks for all the good advice. I'm gonna go out on a limb and say you are not a fan of the q-jet huh? Mufflers because I don't want to go deaf on the highway. Not sold on FM tho. I had Thrush on my last 71 Vette and it sounded great.
I rebuilt/upgraded my stock L-82 engine 4 speed with 66,000 miles in 2014 with a complete bottom end refresh, reconditioning many of the L-82 OEM components like the L-82 rods, L-82 forged crank, etc. with new JE forged Racing pistons, new rod bearings, new oil pump, etc. Based on my research and talking with many experienced forum members along with my local GM Chevy expert builder in my area, I went with AFR's (strongly recommend their heads) BUT the 180 64 CC, not the 195's, despite the 195's flowing slightly more CFM at higher RPM's (where my engine rarely would be), but will be more sluggish than the 180's in the low RPM range, with the 180's having much stronger mid range torque. My experience now 11 years years on with the AFR's is spot on with this assessment.
As noted on previous posts recently, the L-82 cam with some compression is actually pretty impressive for a flat tappet cam and will be even better with 1.6 ratio rockers. My OEM L-82 was running comp cams 1.5 roller tipped rockers at the time of the upgrade which I reused on the rebuilt L-82 355. If you do want to replace the OEM L-82 cam, I would highly recommend my Howard Roller Retrofit cam with .525 Lift/LSA 110/duration 219/225 versus the L-82 cams .450/.460 lift/Duration 222/LSA 114 with the roller cam just making more power everywhere in the power curve versus a flat tappet cam, even with similar specs.
As for the intake and carb choice, the Edelbrock RPM is a good choice BUT will not fit the L-82 OEM dual snorkel cold air cleaner intake system (you will need a drop base open air cleaner), if you plan on keeping the OEM setup and look, like I have and did. I reused the OEM aluminum L-82 intake manifold, mildly ported by my engine expert friend, retaining as much L-82, as possible within reason, considering this 78 C3 is confined to street driving with occasional high rpm blasts. I wasn't looking for maximum HP/TQ everywhere but ended up with serious HP/TQ, even with a few compromises, like the L-82 intake . If I would change my intake manifold, I would consider also the GM SBC ZZ4 intake since in most test I read it produces the most power, very similar to the OEM LT-1 intake BUT 1/2 inch shorter. If you have the OEM L-82 Quadrajet sent it to LARS for a rebuild/tune, but definitely keep, it even if you use a different carb. I did not have my original Qjet and have been using a Holley 4175 650 CFM vacuum secondary spreadbore (which is designed to be a direct replacement for the Qjet) for 40 years with tremendous success on both the OEM L-82 and the L-82 355 with some minor easy tuning.
I run 1 7/8 inch LTHeaders through 2.5 inch duals to C4 corvette Borla Type S SS mufflers, custom fit to a C3......pretty much optimized exhaust for my setup with an incredible unmatched sound, IMO, for a SBC Corvette....no motorboat sounding exhaust or drone but more of a tuned SBC V8 sound...very unique.
Gorgeous car my friend! Love the Blue! Thanks for the great info! Yeah I was hoping to keep the dual snorkel intake as I think it actually helps w air flow and looks stock. I may take your advice on the stock intake.
OP
suggest You ask AFR if their springs in That particular head part number are too strong for a hydraulic flat tappet L82 cam with 1.6:1 RAR.
As in most things; no free lunch: that higher RAR also accelerates the valve opening speed and induces more stress.
If you want more lift, suggest buy more cam. Recomend Mike Jones at Jones Cam Designs of Denver NC USA.
Use plenty of moly paste (or similar extreme-pressure lube) on lifter faces and cam lobes (+ rocker ***** + pushrod tips); But Not on sides of lifters (OD), Not in lifter bores (ID).
Flat Tappet Lifters MUST rotate in bores, But heavy, thick lube on sides can inhibit-prevent that rotation. Flat tappet cam lobe has a slight taper + flat tappet face has a slight convex crown; Both taper + crown together are designed to cause lifters to rotate. If flat tappets do Not rotate, they Will soon die.
I did something similar. On my L82 4spd 3.70 rear, I went with the 60cc Trickflow DHC 60cc heads and a retrofit Howard’s roller cam, 110255-12 with 1.6 roller rockers and headers. Definite lope at 800 rpm but significantly more low end torque than the original L82 setup. Kept the original manifold and quadrajet with 1980 chrome air cleaner cover. Wanted the original look. Had to use valve cover spacers with the roller rockers. I used aftermarket spark plug wires too short to retain the distributor shield.
Wanted to do the Performer RPM manifold but everything I read said it will not fit with the original air cleaner. Regular performer should. I used Quadrajet Power for carb tuning parts and upgrade guidance and was happy with the result. They have good rebuild vids on YouTube.
As someone mentioned, the motors mounts are a weak link. Good thing I had the hood off once I got it back together and noticed the left side motor movement. The mount had separated and the fan was eating the shroud. Put poly mounts in. Haven’t noticed any additional vibration.
No I'm not saying that the quadrapuke is a bad carburetor. Just that it's nearly impossible to rejet with the current almost non existent jetting components.
And yes there are a couple, but only a couple people out there really good at recalibrating one. Once properly set-up. It's a great carb.
personally I tryed 3 times. Seen several people who claimed they understood Quadrajet carburetors. Couldn't get the low end bog out of it. I didn't know of Lars back then.
Put on a RPM intake manifold and Holley carburetor. Had it dialed in in a week. After spending years trying to recalibrate a Quad. Car never ran better.
Never kept the original air filter on my 77. Thought it and all the heat tubes and vacuum lines were just way to ugly.
But everyone is different.
Then a few years ago I went a different route. I went throttle body EFI. Performance is pretty much the same under hard acceleration. But cold starts, warm ups. And general drive ability. Way better. Love the EFI.
Quadrajet? Good luck.
You are putting "top shelf" cylinder heads topped off with Chinese PRW rockers (why cheap out now?) and how have you already determined pushrod length ?
With those heads, when you add good pistons, EFI, and a roller cam, you are way past the price of a junkyard LS swap (which gives you all of that for free, plus no distributor). You are almost to the price of an LS3 crate engine, new from GM, with a warranty.
Before you jump in with both feet, consider just buying a crate engine of any generation, or even a used engine off Facebook. The last two times I convinced myself that repairing a Gen 1 SBC was worthwhile, I got burned by cracked heads, and a cracked intake manifold.
Last edited by Bikespace; Dec 5, 2025 at 09:40 AM.
With those heads, when you add good pistons, EFI, and a roller cam, you are way past the price of a junkyard LS swap (which gives you all of that for free, plus no distributor). You are almost to the price of an LS3 crate engine, new from GM, with a warranty.
Maybe but it won't be original to the car. Keeping all the oem part for if I sell one day.
You are putting "top shelf" cylinder heads topped off with Chinese PRW rockers (why cheap out now?) and how have you already determined pushrod length ?
^^^THIS^^^
Although must determine PR length With following In Place and On Block: a pre-compressed head gasket + head + valvetrain (or light check spring) + rocker arm.
Before attempting to determine PR length, suggest acquire a simple PR Length Check Tool AND a decent caliper that's capable of measuring Twelve inches (common 6-inch caliper too short). Some PR sellers allow buyer to send in their firmly-tighted PR check tool and seller will match PR to that tool's length. Also. acquire a light check valve spring to replace heavy valve spring; so as to Not collapse any hydraulic lifter. OTOH, some folk get pretty close by using the blue plastic rocker arm tool.
Maybe but it won't be original to the car. Keeping all the oem part for if I sell one day.
You can do that, but...
Younger buyers care less and less about original cars.
It is the restomod market that is growing so strongly.
The original car market is somewhat stagnant, unless you have a very rare and high HP original car.
The mid to late 70s cars just do not have a lot of intrinsic value.
The main advantage is the stylish curvy body lines.
At least they are worth more than the C4s.
Might as well build it the way you want!
And drive the wheels off it!
You can do that, but...
Younger buyers care less and less about original cars.
It is the restomod market that is growing so strongly.
The original car market is somewhat stagnant, unless you have a very rare and high HP original car.
The mid to late 70s cars just do not have a lot of intrinsic value.
The main advantage is the stylish curvy body lines.
At least they are worth more than the C4s.
Might as well build it the way you want!
And drive the wheels off it!
Oh trust me, I am. I was going to leave it original because it IS a low mile L82 4spd but 225 HP just aint gonna cut it. Plus its way too quiet! I'm just a traditionalist with the old school small block...400hp will be plenty for me. I AM gonna put a different cam in it because the flat tappet cam will wear down with my AFR 195s springs. Good excuse to get a bigger cam right? lol
A retro roller cam is a good way to go without the worry of wiped lobes so common with modern flat tappet design and lobe quality, spring rates and oil formulations. It’s definitely an extra cost though.
Headers and dual exhaust will make your exhaust significantly louder even with the stock mufflers. My car came with Dynomax 17757 turbo mufflers which have a deep vintage sound but are not obnoxiously loud. I have heard others complain of some drone at low rpm’s but hasn’t been a problem I have noticed. With 4 speed, 3.55+ gears and higher cruise rpm’s you are going to be out of the drone range.
As suggested earlier, I would strongly encourage you to consider the AFR 180 64 CC heads over the 195 AFR's on a SBC 350/355 that is not going to make over 450+Gross HP and/or will spend most of its life sub 4,500 RPM with occasional revs to 5,500-6,000 RPM. The longer runners on the 195 will definitely make the motor more sluggish than the 180's at lower revs/RPMS and will not be optimal for the strongest mid rang TQ in the 2500-4500 RPM range. Definitely go roller cam. I feel my Howards Roller cam .525 lift/LSA 110/219/225 Duration is just about perfect for a street L-82 4 speed. However, if I had to replace that roller, I would aim for the same duration 220/225 (best for bottom end power with strong Midrange TQ), along with LSA110 but would look for a bit more lift .530-.535 since the AFR's are that good at moving the air. Probs a few more Gross HP with slightly more lift, IMO.....
L82 Upgrades
