The LA3 is the aggressive computer and it's in the '87-'88 TC's. You'll need the large VAM to go along with that. You can't tell from the part # which ECU it is. All ECU's have a 3 digit code stamped on them. Note LA3 in the pic.
LA3 computer
I believe the wiring conversion will be the same. You still have to wire in the VAM, the only difference is the '86 has a small VAM instead of a large one. Go to Stinger's website
www.stinger-performance.com He has a message board on there. Ask him that question and I'm sure he'll give you an answer.
I see you posted in my sticky thread too. The fuel pump should be the same in your TC and Mustang.