Obviously 94-95s will fit....so will 96-98. Direct bolt in. the earlier fox axle will bolt in as well BUT they're drums and also more narrow (not sure by how much exactly). 99-04 will drop in as well BUT they are 3/4" wider on EACH side so it will push your tires out a bit furter....which actually LOOKS better. Everything else is a direct bolt on! I'd SUGGEST retaining the brake lines from the bottom of the car and across the axle on the car the 8.8 is getting installed in as a JUST IN CASE there are some differences in the years that I've never seen.
I've put a 95 axle under an 03 cobra so I know its a cake walk, car to car.