350 corvette engine in Trans Am GTA - Third Generation F-Body Message Boards

highway22002 · 03-05-2002, 02:45 AM

Hi!

It looks like I have a '89 350 corvette engine in my '89 Trans Am GTA. So the question: what should be compression ratio
for this engine? Now it is about 10. Is it good?

thanks,
Marcin

Ukraine Train · 03-05-2002, 08:47 AM

welcome to the boards,

stock i think those engines were about 9.5:1. The corvette aluminum heads are 58cc as opposed to the f-body ones which are 64cc. F-bodies have a compression of 9.3:1 with the 64cc heads. The corvettes only have a slightly higher stock compression because they used a thicker head gasket than the f-bodies at the factory to lower it. You probably have standard thickness head gaskets now and that's why it's 10:1.

This is exactly how my engine is being built, with the standard gaskets. You probably should be using high octane gas like 91 or 93.

highway22002 · 03-05-2002, 09:26 AM

Thanks for help.
So its all ok, I suppose