Will the 3970010 casting number block mount easily to a 1986 trans am? Will I have to fabricate anything?

 

The mounting provisions on the SBCs are the same, so they're all interchangeable. That block has the dipstick tube on the drivers side, so you might need to tweak it a little to clear stock manifolds if you're not using headers. It's also a one piece rear main seal block, so you'd need to change the flywheel.

 

The original '86 engine is 1-piece RMS; the 010 is 2-piece RMS. (will need to change the flexplate/flywheel)

 

Ya, my bad... I mean it's a two-piece block.

 

BTDT. 153t flywheel for a 2pc rms engine, headers to clear the dipstick tube, everything else will bolt up fine.