Not knowing any better, I bought upholstery for the later seats, and found that it does NOT fit on the '87-89 seats.I've also had some fun with using Fox4 (SN95) components on my car. The brake booster on the Fox4 is MUCH bigger than ones used up until 1993. The engine compartment appears to be the same between Fox and Fox4, but it's not. I had to slot the mounting holes A LOT, as well as "clearance" the strut tower to get the Fox4 brake booster in my car.The Cobra IRS. I had planned to use it on my car, and even bought one. Yes, the mounting points are the same, so you CAN bolt it up, BUT, the axle shafts and control arms make for a MUCH wider rear track width and there was just no way I could make it work on my car without having custom components made. WTF?PMGR Starter. A cool upgrade for the older cars right? MAKE SURE YOU GET THE RIGHT ONE. I went to the boneyard and grabbed a starter out of a 1994 F150. Turns out, when they made the change to the Permanent Magnet Gear Reduction starter, in the trucks (F150, Bronco, Econoline, etc), they started using a different starter for the manual trans trucks. The "nose" is much shorter, and the gear will just barely brush your flywheel, doing damage while it's there. All Mustangs used the same starter as the AUTOMATIC trucks.