Strange Question

[rbrack]

Alright, at the risk of sounding stupid, I'm going to go ahead and ask. I'm pretty sure it won't work, but I just want confirmation. Will LS1 heads fit on an old Chevy SB 350 motor?

[hammertime]

nope

[02z28ls1]

I'm almost afraid to ask-but-why would you want to?

[hammertime]

Newer Chevy Vortec truck heads fit older SBC engines, offer a modern combustion chamber and better flow over most traditional iron heads. They do required a different intake manifold, and some reworking of EGR if required for your application.

But those were only on 96+ 5.7L (350ci) Vortec truck engines. 99+ 4.8L, 5.3L and 6.0L truck engines are members of the LS1 family and do not interchange.

[mrr23]

nope. and here's pics so you can see the differences.

http://www.ls1.com/forums/showthread...highlight=head

[johuckabee]

What is the point of the offset ports on old motors. On modern engines the ports are evenly spaced. Whats the dilly.

[RainMan]

What is the point of the offset ports on old motors. On modern engines the ports are evenly spaced. Whats the dilly.

That's the original production design of the SBC that dates back to the mid 1950's. What the engineers were thinking, who knows. But the engine design was one of the most popular in automotive history. It reigned for 37 years!

The Gen III / IV engines are completely different than the original Gen I SBC and Gen II LT1/LT4. Even the firing order is different. I don't think there is a single piece of internal hardware that is interchangeable, not even the valve keepers.

Other than some close similarities in displacement (5.7L), there is only one internal dimension shared between all small Chevy engines from 1955 to date! 4.4 inch bore spacing. Second and Third links below shows LSX bore Spacing at 4.4" like it's Gen I & II predecessors. Even the new LS7 427CID still shares the 4.4" Bore Spacing.

http://www.chevyhiperformance.com/techarticles/95098/

http://www.smokemup.com/tech/ls1.php

http://en.wikipedia.org/wiki/GM_LS_engine

Hope this helps.


Correction Department: LS1 & 6 also share the SBC's second design Connecting Rod journal diameter of 2.10" (Big End). LS2 = 2.224", LS7 ??
Early SBC's used a 2.00" Rod Journal. LSX's use longer rods and taller block deck. SBC deck height = 9.025, LS1 & 6 = 9.24"

[cuz]

no.

[RainMan]

no.

No, to what?

[Street Lethal]

Alright, at the risk of sounding stupid, I'm going to go ahead and ask. I'm pretty sure it won't work, but I just want confirmation. Will LS1 heads fit on an old Chevy SB 350 motor?

No, but the fourth generation aluminum LT1 heads do. With a little pursuasion, they'll flow just as good as any aftermarket LS1 head out there. Some modification (aluminum filling) needs to be done, but this is nothing that a credible machine shop couldn't handle...

[rbrack]

I'm almost afraid to ask-but-why would you want to?

Well, I am building a 383 Stroker to install in a Fiero. I have the motor built up to the heads. Since I am planning a head/cam swap in the Trans Am, I was curious as to whether or not I could take the heads, intake manifold, and exhaust manifold from the Trans Am and install them on the motor going in the Fiero.

[MrMiracle]

That's the original production design of the SBC that dates back to the mid 1950's. What the engineers were thinking, who knows. But the engine design was one of the most popular in automotive history. It reigned for 37 years!

They were thinking of making the intake easier to design. To make airflow to each cylinder as even as possible, you want as equal a distance from the carb as possible. Cramming the two intakes together makes that pretty easy.

Conversely it makes exhaust design pretty darn wacky. Two together and two way out there.

[02z28ls1]

Well, I am building a 383 Stroker to install in a Fiero. I have the motor built up to the heads. Since I am planning a head/cam swap in the Trans Am, I was curious as to whether or not I could take the heads, intake manifold, and exhaust manifold from the Trans Am and install them on the motor going in the Fiero.

Well that's a better answer than I was thinking-sometimes if you explain what you are trying to do in full you can get more appropriate answers. Once you get the heads off the Trans Am you will see the answer to your question. There are plenty of aftermarket heads available for 383 that will work kick-ass. Try to match up the cam w/the heads you pick for best results.