I recently got a 1986 s10 2.8L TBI that had blown a head gasket. When I torn down the motor I found that ya the head gasket was blown but it also has 2 spun piston bearings so the crank is toast. It did not spin any bearings on the mains so it looks like the block is ok. My questions is can I use this block and heads on my 1990 3.1 camaro. I remember reading something about oil holes and valve sizes but I cant find it now. Is the difference between the 2.8 and 3.1 just the crank, pistons and rods?

 

There's a few other small differences, but basically the only difference is the crank, rods & pistons. Do a double check on the main sizes, I think the early small main blocks may have been carried on into '86 s10's. Won't be compatible if that's the case.

 

I thought 2.8 and 3.1 pistons are the same. As in, a 3.1 is just a stroked 2.8....

 

Somewhere in 85-86(I dont know the exact time) the 2.8 went from having small mains to the larger mains that are in the 85/86+ 2.8s and 3.1s. As for the difference between the 2.8 and 3.1...the pistons are what is different.