Will a 1987 block work on a 1990?
 

I have what I believe is a complete 1987 motor with low miles. I bought a car with no block just all the parts to swap onto a new block (I hope all) are there any differences in the blocks that would not allow me to use it with all my hardware from the 1990

The '87 block won't work. You won't be able to bolt up the lower intake from the '90 onto the '87 block. There are some other differences that I can't think of at the moment.

I will have to file a section of the mounting for the Intake.