Hello all. I have a 71 with a stock LS5 454 that is getting tired. The engine is mated up with a m21 4spd and 308 in the rear. Being that winter is fast approaching and I will have 6 mos of down time. I was pondering options of an engine rebuild. Headers are a given, but not quite sure what would be the best route for the engine. I am leaning toward rebuilding it, being it has the original engine. New cam/pistons/head etc and was curious to what some of you folks out there have had success with. I am also thinking about upgrading tranny to keisler set up sometime after the eingine upgrade. This will be a street car, I currently drive the vette everyday weather alows in the summer. Looking to be able to run on premium gas. Really looking for an all around good package. Budget right now say is $5000 on the high end. Any and all idea/experiences are welcome.

 

Where are you located. If you fill in your profile, someone may be able to give you the name of a local rebuilder in your area that they have experience with.

Welcome to the forum.

 

Thanks for the heads up.

 

to get your comp. up Edelbrock has a head they call the
performer high compression 454-0 it uses a 100 cc combustion
chamber, 290cc runner oval port, 2.19 intake valve 1.88 ex valve.
good hydraulic roller cam. they claim 9.2 comp. with a flat top piston.
if you want more comp. you will have to go with a domed piston.
part # for one complete head 60499

 

AFR has some oval port heads that look pretty good. A heads/cam/exhaust setup would probably rock, maybe swap in a 3.55 rearend.

 

Is a 3:55 low enough for all the torque
I have a 4:11 right now and stay in first and second gear for about a half second. All the low end torque pull is missing

I was thinking of a 308? Is the 3:55 the happy medium?
Sorry to hijack the thread...

 

I am leaning toward converting to the keisler 5 speed after the engine work. I think it would work well with the 308 rear end. superdad no worries on the hijacking the thread.

 

3.08 x a .082 overdrive would be the same as having a 2.50
rear 3.08 with a .064 overdrive gives you 2.00.

 

Hello AK454,

Whenever you're ready for the tranny, just give me a call, and I'll help you pick the gears

 

For the engine, freshen it up by boring it .030" over. Use forged pistons, and go with a 9:1 compression ratio.

Use ARP bolts for your rods and crank caps. Hot-tank and magnaflux the block... Also, line-bore the block, if it needs it. Balance the rotating assembly (make sure to have the new clutch and flywheel included in the balancing, to make sure it's TRULY balanced).

Go with your stock heads, but clean them up with a pocket-port and bowl-blend. Retrofit 2.25 and 1.88 valves, set them up to run up to .600" lift, and roller valve springs.

Use a street hydraulic roller, with an operating range of 2000-5000 RPM. Go with the torker 2-O manifold, and a either a Demon 650 or a Holley 750 vacuum-secondary carb.

If you can find an HEI distributor, go with that (more reliable). Make sure it has a good pickup module, and a supercoil.

Go with headers of at least 1 3/4" primary diameter, feeding to a dual exhaust system of at least 2 1/2". Make sure to have a cross-over pipe on the exhaust, and use free-flowing mufflers.

You should easily see 500HP, 500 lbs.-ft of torque, and do it all on junk pump-gas... And it'll be dead-on reliable.

I know a lot of people espouse the viewpoint that you should go with high-flowing (high-$$$) heads, but a decent head rebuild will set you back somewhere around $600... And the big-$$$ heads flow well at high-RPMs, but for a street car, you need smaller ports that will maintain flow velocity at lower RPMs, and keep the fuel adequately atomized in the airstream... Big-port heads will lower velocity, reduce the fuel entrained in the airstream, and reduce throttle-response...

With this combination, you'll stay easily within your $5K budget, have GOBS of torque, and have a perpetual grin on your face... And best of all, it'll work perfectly with your 3.08 gears!!!

JMHO.

 

Hey guys thanks for all the suggestions. I had thought about using the old heads and just having them opend up a bit. I already have 2 1/2 inch exhaust system just need to match it up with some headers. If any one else has some good suggestions, I am more than willing to listen.

 

I would keep the original engine all original. Replace it with a GM crate 454H.O. I have one in my 72 LS5, plenty of H.P. and Torq. If you have a numbers matching car, I would keep it that way. Just my opinion

 

502HO would be better - or ZZ502 even better

 

Mine came with the 454