Will a 2000 Ford Mustang rear end fit 1996 Mustang?

No, a 2000 Ford Mustang rear end will not fit a 1996 Ford Mustang without significant modifications. The 1994-2004 Mustangs are commonly grouped together, but there are differences, particularly in the rear suspension geometry and mounting points between the SN95 (1994-1998) and the New Edge (1999-2004) generations. The axle width, spring perches, and mounting brackets are different. While some parts *might* be similar, a direct swap is not possible.