This is a common topic here and a search should produce lots of options.
I used the rear from a '73 Chevelle wagon under mine. Had to cut off the coil and trailing arm stuff and weld on spring pads, but width wise it is perfect, and coming from a wagon, mine had 11 inch brakes which have served me well too.
Wheel mounting surface to wheel mounting surface is a better measurement, and about 62 inches is correct.
