hey! frist post here...
well i wanted to know if a 1987 Toyota Supra [Turbo] Exhaust with go on a 1987 Toyota Supra [Non-Turbo]?

It will fit under the car no problem, and the 3" piping on an N/A isn't a big deal (it will be louder of coarse) but you will have to modify the test pipe that replaces the cat becuase the turbo DP is a slightly different length.

I'm not replacing the Cat with a Test Pipe. Will it still fit?

Nope, you'll have to cut up that new exhaust I believe. Only one way to find out for sure though, stick it in the car and see what happens.

u will loose a little low end but u will have some good top end!