The SN95 rear ends are approximately 1.5" wider as well. The housings are all the same width. What makes them wider is the disc brake assemblies which requires each axle to be 0.75" longer than a Fox Mustang axle. Same deal with the 87-88 Turbo Coupe.
I know that the 97 Cobra wheels fit perfectly so whatever that back space is works with a 17 X 8 wheel. I have 255/40/17's on all four corners.
Darren