Just recently I found out that 96 f350's have a rotor that is not quite as deep. It's 3.1 thick vs, 3.5 for your rotor. So, it cuts about 3/8 off your total thickness of spacer. It's 13" round though, so 17" or larger wheels would definately be required for that caliper.
I'm planning on using a spacer too, but I'm using slightly smaller calipers. I think I'll end up with only about 3/4" of spacer at the most.
