'84 thru '87 engine compatibility

[rodman99999]

Can someone tell me if the long blocks were the same between '84 and '87? I think I read somewhere that the changes were all in the induction, ECM and sensors. I need an engine and don't want to make any mistakes. Thanx for any insights.

 

[rodman99999]

ttt

 

[Joe Cancer]

Block, pistons and rings are different.
Crankshaft,cam,heads and rods are the same.