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To all the veterans on here.......toobroketoretire? You think?
I am the OP. I would appreciate more information about building the engine I am asking about, and less about 427 versus 454. Its not what I was asking. I need more information and details about achieving the engine I want to build from those who know. Just asking. What blocks would be best, what heads, what intake, what cam, what carb, etc. I want an original looking engine, with the limitations I set in the beginning, for the least amount of money without sacrificing longevity. That is the information I wish I could get here.
Where's Jebby? Leigh? Mako? Vortecpro Gkull? ....all probably not interested in back and forth about 27 cubic inches. And Mark at Vortecpro has already PM'd me, and I expect we will be doing business in the future.
I have an unmolested '67 L36, and a tired '72 LS5. The '72's engine was rebuilt this summer. I wanted much the same as you are seeking: stock looking (started with all dated original components that I did not want to lose from the car); good driveability; strong on the street but not lopey; no need for high rpm (I chicken out at 4000-4500 rpm and no longer feel the need to prove my testosterone) But, I also wanted to maximize performance on the internals, you know, walk softly with a bigger stick? The question is how big of a stick do you need, want, and can afford?
My engine was completely gone over by a one-man shop who builds higher-end engines (~$10k-$15k+) for drag cars, circle dirt cars, and street cars. I followed his recommendations given my input above. We bumped the pistons to get a 9.5:1 ratio, bored .030 over the existing factory bore, did new bronze valve guides, all new valve train, bearings, etc. He polished and balanced my factory crank, rods and new pistons, and put in a mild flat tappet cam (very close to factory grind). In all, it is really just a stock rebuild except for the minor CR increase . On the dyno it came in at right around equal 400hp - 400 ftlb torque - places it right at the '70/'71 454 performance. There's nothing shabby about that for a street driven car and I'm happy that it'll be fun to drive, have a good burble-idle at stoplights, and pull away strongly. Total cost was ~$6000 with no block/heads/intake purchases.
454? 427? I don't think it matters all that much as they look almost identical from the outside and all of the stock intake and exhaust manifolds bolt to either. You mentioned an LS7 block and components for $1500? Jump on that. You may not use the pistons (CR?) but hopefully the crank and rods are not bent or so race-specialized as to require race components or have a shorter life than street parts. Passing a crack and machining inspection is mandatory. With the heads that you install, make sure they have all of the proper bracket holes to mount whatever engine driven accessories your car may have.
Last edited by barkingrats; Dec 5, 2020 at 02:10 PM.
I worry about flat tappet cams simply because of the horror stories with break in, ZDDP, etc. I don't have to have roller stuff.
I think your worry is unnecessary. The roller cam, lifters, and rockers would have increased the rebuild price by over $1000 and may not have fit under my stock valve covers - we didn't try it but that was his concern. My engine guy calmed my similar concerns about flat tappet break-in and zinc. He insisted on breaking in the engine on his dyno so that he knew it was done right. I was happy that he was able to do that because it took that worry from me. After that you just need to buy the proper oil. He recommended the Driven brand and uses it in his late-'60s Mustang. (Summit Racing sells it and gives free shipping if you spend $100 and up - 1 case of 10W-30 and two WIX filters.)
I have searched all threads on the subject already, but since I am bored, I decided to start another. I have just acquired a 69 Convertible project, without an engine, and intend to build a big block for it. After all the custom and performance work I did on my 77, I learned two things.
1. Every time you "upgrade" something, the ripple effect is that something else needs changed.....i.e. slippery slope.
2. It cost way more money when you "upgrade" the car.......lots more.
So, with the 69, I have decided firmly that I want to build the car as close to original as reasonable.....not NCRS crazy, but just build it the way Chevrolet did, and capture what the car was in June of 69 when it was built. Not overthink it, or over build it. BUT......given I have NO engine at all, I know enough to know that I can build a big block that looks original, but might just have a little more juice built into it. There is ONE firm point, and I will not budge, I want to use stock GM cast iron exhaust manifolds. NO headers. As soon as you go headers, you no longer can buy store bought exhaust systems,.....and then you are down the rabbit hole of upgrade cost inflation. Plus, I like the looks of cast iron Big Block manifolds. I also want to use factory style big block hood,....not a fake L88 hood on a car without an L88 engine, so I believe that limits my intake manifold choices.
SO.....what I know is that the exhaust system and intake manifolds are big corks when it comes to performance upgrades. My question is to all of you, what can I do to make a big block perform UP TO THE LIMITATIONS of the intake that will fit under the hood and the cast iron Big Block manifolds / exhaust system......OR is it not even worth the effort and just build a stock motor. And when I say performance, I mean torque......I will never drive the car over 70 mph, will never race it, and am not showing off to anyone. These are my thoughts so far.
- Build a 454 instead of a 427, i.e. LS5 style engine just to get more torque. At what displacement does my self imposed limitations be a waste of effort? 454, 496, what? Or just build a 427..
- Aluminum heads for weight reduction primarily........AFR heads with low rise intake and cork exhaust would be stupid waste. Maybe Edelbrock Performer heads, or other lower performance aluminum heads, or is nothing worth doing? i.e should I just build a factory spec'd L36 the way it was built in 69.
- Cam?
- It appears factory 427 parts are extremely expensive just because,....so why not just go 454 LS5 stuff that seems cheaper. I want to control the costs on this project as opposed to the out of control costs I created with the 77.
Get my drift....looking for a reasonable way to enhance performance of an original looking engine, within my self imposed limitations. What do you say?
I can tell you this: my 9.3 comp 467 with a 228/238 hyd roller cam made 532 HP with 236 peanut port heads, with the factory sunken cast iron intake with a Q-Jet, great vacuum 750 RPM idle, but it was tested with headers. I've done blueprinted L72 427s that made 530 through exhaust manifolds, but with the tall factory 163 intake.
Last edited by Vortecpro; Dec 5, 2020 at 06:32 PM.
Thanks to all of you that actually posted comments to help answer my questions. I do NOT appreciate the poster that started a back and forth about 27 cubic inches......all it did is create a thread that valuable input was not posted because many people don't read the entire thread once it gets into childish behavior. There are guys who did not post here that I respect, and I suspect its because of this stupid BS. Thanks toobroketooretire, no matter what you call yourself today.
To Mark at Vortecpro.....when the time comes, I will be probably be calling you.
Last edited by Shovels and Vettes; Dec 6, 2020 at 07:18 AM.
I can get a factory LS7 big block, crank, rods and pistons locally for $1500. It was in a race car, so I would need to get the block inspected before I would buy. It is my understanding the LS7 was a performance engine available from GM, never put in a C3 Corvette. High compression...in fact too high for pump gas...so pistons could be replaced. I have to do more research on this....anybody have an opinion on this?
You should be able to get a cleaned and checked 454 block from a machine shop for around 400.00 The only thing that made it an LS-7 was heads and compression which was too high for pump gas. Look on ebay for rotating assemblies just to give you an idea, but they are fairly inexpensive, and if you just go with a non roller cam kit from Howards they are less than 400.00 for cam lifters, springs, and timing chain+gears. My last 3 builds I did not use roller cams, and they still make really good power.
If you do go roller I recommend the Howards max effort hydraulic that are lighter because they are super quiet. I have used practically every brand, and these are by far the best IMO.
Here are the lifters I like if you do go roller.
Last edited by centuryoldracer; Dec 6, 2020 at 02:45 PM.
You should be able to get a cleaned and checked 454 block from a machine shop for around 400.00 The only thing that made it an LS-7 was heads and compression which was too high for pump gas. Look on ebay for rotating assemblies just to give you an idea, but they are fairly inexpensive, and if you just go with a non roller cam kit from Howards they are less than 400.00 for cam lifters, springs, and timing chain+gears. My last 3 builds I did not use roller cams, and they still make really good power.
If you do go roller I recommend the Howards max effort hydraulic that are lighter because they are super quiet. I have used practically every brand, and these are by far the best IMO.
Here are the lifters I like if you do go roller.
Thanks man,.....this is the good kind of information I was looking for.
I tried to explain it,.....but I guess it didn't work....here I go againl
- Stock iron exhaust manifold into 2-1/2 inch exhaust pipes, and some appropriate mufflers. Why? I spent thousands of dollars on super duper headers and mndrel bent exhaust system on my 77....and the still did not fit. I just want to buy simple factory system that fits....tired of the BS.
- Intake manifold that will fit under factory style big block hood....NOT L88 hood. My understanding that limits it to a few factory manifolds that are poor performers compared to others. Edelbrock nor anyone else apparently produces these,...so its used GM. I also would prefer a Holley, but I suppose the right carb is a Quadrajet.
- 15 X 8 factory size tires,... i.e. Coker redline replicas, BF Goodrich, or Coopers.....NONE of which are great performers so massive torque is simply unnecessary when all I will do is spin.
- Factory appearance externally.
- Mechanical fuel pump
- Factory 4-speed clutch and transmission
These are all required. I will not start down the path of changes these for extra performance. I will never drive over 70 mph, I don't race, and I don't need to do burnouts in front of people. I simply want big block power to accelerate fast when I want to. I understand that much of what I want is far less than what it could be.
SO....with these parameters, how do I get there.
- I could build a 427 with exactly the parts GM put into the engine in 69. BUT, this stuff is expensive compared to a 454. I would do this if it wasn't for the ridiculous prices on 427 parts.
- I could build a LS5 with exactly the parts GM put into the engine in early 70's.....or I could use the LS5 block and use a crank for a 427 or 496. don't care if that is not "original" for a 69. I am putting the 427 emblems on the hood no matter what engine is in the car. It appears this would be much less expensive than buying 427 parts.
- THEN.....I am asking you guys to give me other options. Jim says a 496.....okay, maybe that's it.....and I get that, as the extra cubes should compensate somewhat for my restrictive choices, and still give me power. I keep hearing about late model truck engine blocks that can be bought for little,...and go from there.
As for what I want....I want a very torquey powerful big block that gives me the thrill everyone talks about when talking about C3 big block engines. My 77 now has a 406, built by Jim Barth, that I will have on the road in the spring. It cost me alot of money. It has all great components. I might have a more powerful SBC than this 69 big block with my limitations. Fine. I played ALL the upgrade games with this 77.....it has all the good stuff. I cannot do it again with this 69.....it simply is too much money. I like the idea of embracing what the 69 was in 69. I don't want to have to make all those "upgrade" decisions on the 69.....I just want it to be original. So, maybe the answer is just build a factory 427 with original parts. Just seems that there is a few things I could do, within my limitations, to build a big block sleeper for a little less money, and possible tweek out a little more power. And it would look original.
Does that help?
Lastly......I want it to be a quality build with good components, but it does not have to be the absolute best of everything. I worry about flat tappet cams simply because of the horror stories with break in, ZDDP, etc. I don't have to have roller stuff.
That certainly does help. Though I’d question how much work/money you want in the rest of your drivetrain? What is the plan for trans and differential?
You likely won’t be hooking up with street radials, so it isn’t as critical, but you can still make a heck of a lot of power with manifolds and a low rise intake. Again, cam selection will be critical to work with the more restrictive exhaust, but any competent grinder should be able to handle that.
Best performance for a street car will come with displacement. Go for as much as possible. If that’s just a rebuild on a LS5, do it. If it’s a 496, do that. Large displacement tends to help everything but the fuel economy, including the low RPM power you enjoy so much.
Up to you if you want it to look stock or not. But that may limit valve train options.
That certainly does help. Though I’d question how much work/money you want in the rest of your drivetrain? What is the plan for trans and differential?
You likely won’t be hooking up with street radials, so it isn’t as critical, but you can still make a heck of a lot of power with manifolds and a low rise intake. Again, cam selection will be critical to work with the more restrictive exhaust, but any competent grinder should be able to handle that.
Best performance for a street car will come with displacement. Go for as much as possible. If that’s just a rebuild on a LS5, do it. If it’s a 496, do that. Large displacement tends to help everything but the fuel economy, including the low RPM power you enjoy so much.
Up to you if you want it to look stock or not. But that may limit valve train options.
Yes,....I will be using 15 X 8 factory size tires....most likely the Coker Redline retro tires, OR, Cooper or Goodrich. All of which cannot handle much before spinning,....so why I don't need to spend alot on massive torque.
The driveline will be 1969 stock, i.e.Muncie M20 4 speed, factory size driveshafts, and either a 336 or 308 differential, rebuilt by Gary R. or Bairs. I am determined to resist most upgrades out there. I did all of them on my 77, and its cool, but this time, I want to avoid it. Its an endless rabbit hole where one thing leads to the next, all of which cost huge money. I will probably use F41 suspension i.e. 7 leaf steel spring from Eaton, I may concede to Bilstein shocks?, will use factory struts, factory front suspension, all rubber bushings. Again.....factory stock. I embrace it, and it makes the car special to me in the sense I can experience what GM built, and not try to overthink their design. All I am going to do is drive the car. My 77 can be my performance machine.
This is all key to my questions.......upgrades all are great as long as you do it as a package. Its why I established my restrictions and limitations. There are plenty of threads on building power and performance with no limits, I need to know how to build the best power UP TO the limits I have placed.......and that can be more difficult.
Last edited by Shovels and Vettes; Dec 7, 2020 at 11:28 AM.
Since we are on a 427/454 build topic. I need some insight on what the manifold on the left is from.(both are aluminum)
thanks!
No casting numbers or brand stamp manifold on left. Original 801 427 intake on right. oval ports are much bigger on the unmarked intake on left. Is this from a 454?
Build a 468.......nobody will ever know whats in it.
I am building one this winter.....and if I put 427 emblems on it.....you will think it is the best running 427 you ever felt.
Since we are on a 427/454 build topic. I need some insight on what the manifold on the left is from.(both are aluminum)
thanks!
No casting numbers or brand stamp manifold on left. Original 801 427 intake on right. oval ports are much bigger on the unmarked intake on left. Is this from a 454?
I'm not sure but I think they made a marine version. ???
Build a 468.......nobody will ever know whats in it.
I am building one this winter.....and if I put 427 emblems on it.....you will think it is the best running 427 you ever felt.
Build a 468.......nobody will ever know whats in it.
I am building one this winter.....and if I put 427 emblems on it.....you will think it is the best running 427 you ever felt.
Jebby
I did this with my Camaro, tell everyone it's a 396.
From what I researched (BB new to me), a 468 is a 454 with 0.060 overbore. Is that the limit of overbore on a BB? i.e. after that you have to buy a new block?
From what I researched (BB new to me), a 468 is a 454 with 0.060 overbore. Is that the limit of overbore on a BB? i.e. after that you have to buy a new block?
No.....I have run many Mark IV's and Gen %'s at 4.350 bore.......it is the next step up shelf piston, for 475 cubic inches but the block is done at that point IMHO. I have seen them at 4.380 but sonic checked and unreliable as the bore is so big and the wall so thin it loses ring seal. I just always go .060 because it helps the heads breathe and doesn't hurt anything. A 496 is 4.310 and very common.
No.....I have run many Mark IV's and Gen %'s at 4.350 bore.......it is the next step up shelf piston, for 475 cubic inches but the block is done at that point IMHO. I have seen them at 4.380 but sonic checked and unreliable as the bore is so big and the wall so thin it loses ring seal. I just always go .060 because it helps the heads breathe and doesn't hurt anything. A 496 is 4.310 and very common.
Jebby
Thanks Jebby. That's good. I just want to know that I have one more bore job before the block is trashed. Realistically, I hope I never need it, but I figure I should at least have one more overhaul. I did the same on the SBC 406 in my 77.
Given I have nothing yet, in terms of an engine, it seems to me I would be smarter to find a later model Gen VI block, with factory hydraulic roller capacity (cheaper), i.e. if going hydraulic roller, it is cheaper with factory setup than retro style. .....of course assuming I can get it at a reasonable price. From what I understand, the Gen VI does have mechanical fuel pump, and clutch attach bosses / holes. I see no downside in these blocks,......but welcome any input on that. And if I get a junk yard engine, I might end up with a good crank, parts and pieces? What do you say?
To all the veterans on here.......toobroketoretire? You think?
I am the OP. I would appreciate more information about building the engine I am asking about, and less about 427 versus 454. Its not what I was asking. I need more information and details about achieving the engine I want to build from those who know. Just asking. What blocks would be best, what heads, what intake, what cam, what carb, etc. I want an original looking engine, with the limitations I set in the beginning, for the least amount of money without sacrificing longevity. That is the information I wish I could get here.
Where's Jebby? Leigh? Mako? Vortecpro Gkull? ....all probably not interested in back and forth about 27 cubic inches. And Mark at Vortecpro has already PM'd me, and I expect we will be doing business in the future.
That’s EXACTLY who it sounds like. Probably yet another alias.....
