engine swap

Not a good idea, IMHO. You'd be better off selling your 5.0 engine and buying a 4.6 engine.

The 5.0 will fit in the T-Bird, but you'll have to swap the trans too. Because the engines are different, 5.0/4.6, the wiring harnesses and computers will be different. The transmissions are different as I'm pretty sure the 93 has a computer controlled trans and the 87 has an AOD with TV trans control.

If you live in a state with any emissions check at all, you're really in trouble. If not, you can probably get by with it.

CJB

Actually they still had 5.0's in '93, not 4.6's, so it should be easy as pie. I would say it should drop right in place of the original. Wiring should probably also hook up directly as I know they DID in fact have MPFI in '87. Also, the T-bird and cougar still had the regular AOD with the throttle valve cable, not the computer controlled one. The 4R70W didn't make it's way into the MN-12 platform until 1994. Everything is a direct swap.

If that's true, I stand corrected.

CJB