Funny, my seats from my 89 would not work in my 95. They were much more comfy. My driveline, I never tried to switch over, but that really has more to do with the engine and transmission than anything else, although the length is the same.
I find it odd that any time I have gone to buy suspension parts for my 95, they ask me if it's for a 94/95 or for the 87-93 then since the suspension parts all transfer over....Oh wait, they don't ALL transfer over.
Taken from your refrenced web page:
For 1994, the Mustang underwent its first major redesign in 15 years. The new design, code named "SN-95" by
Ford, was still
based on the "Fox" platform, but featured dramatically new styling...
Being "based" on something, does not make it the same. The 94-up mustangs are significantly different than the 79-93's. Saying that the 94 and up is a Fox is like saying that an orange is an apple because their both round. Thats all I'm saying. The94-98's are generally known as SN-95's, while the 79-93's are generally known as Fox's. Ford redesigned the Fox platform to make it wider and stronger. This is why it is wider, and weighs more.