Hello All,
I am currently restoring a 1987 IROC 5.7 L98. The engine is completely toasted. I have a 1987 Corvette long block on hand. What I am wondering is, can anyone tell me if the 87 vette short block uses the same internals as the 87 IROC 5.7 short block? The stock IROC heads are still useable and I would like to build the IROC engine back to stock specs. Just concerned about compression ratio using a vette shortblock, ect... Thanks for your help!!!!

 

It should be close enough. The Corvette would have had aluminum heads, but the rest of the engine should be close enough to the same to not be a problem. If anything the compression ratio will go down with Camaro L98 heads.

 

The short blocks are essentially the same.

The Vette had higher compression, BUTT, with aluminum heads, that is REQUIRED to maintain equivalent power output to iron heads. So yes, the compression WILL go down, but it's not like you'd be losing anything. And in fact, the power from the F-body L98 and the Vette version in factory trim wasn't much different.

As Drew said, it's close enough; I doubt you could tell the difference between the 2 after it's installed, either by appearance or performance, if you use the top end from the F-body.