I am pretty sure you can simply swap to earlier rotors to get the 4.5 bolt pattern on the front, with no modifications to the brakes. 82-85 rotors maybe? I would think you could do the same with axles and rear brakes. I'm putting an 8 3/4 from an early 70's truck under my 88, but I'm keeping the 5.5 bolt pattern. A few years ago, I got a pair of 8 3/4 truck axles with the 5.5 bolt pattern from
@Righty Tighty and will just swap the brakes from the 9 1/4 I'm taking out. Same backing plates and offset. I'm having to go the other direction on the gas tank, to get one that will accept a pump compatible with the MPFI on the 5.9 Magnum going in. You may be able to just modify the tank you have by disabling the pump and straight piping a new pickup while leaving the gas gauge sender in place.
