i have been working on a 86 trans am that i bought cheap for a parts car with a bad 305 carbed motor and a richmond 5 speed. and the car grew on me so im fixing it up. it had a t5 stock and it has that bellhousing with an adapter plate. and the stock flywheel. i know 87 1 peice rear main seal flywheels are different but i dont know about 86 so do i need a new flywheel. im putting a late 70s 350 in it

 

if you are using a 70's block, its a 2 pc rear main seal, so you need a flywheel for a 2 pc setup

 

ya but im trying to figure out what the one i have is the one from a 86 305 is

 

everything i have tells me that 86 and up blocks were 1 pc rear main.
so as long as the block is an 86, it should be 1 pc.