My 38 1.5 ton came with 3 different size tires on it, thanks to previous owners ingenuity. Another thing you have to watch is rim depth. The deeper rim tire combo for 8.25x20 tires may rub the rear springs or ebrake cables on the inside, they did on mine. If you change to the dana axle set up others have mentioned you will also need to change the transmission and drive shaft to open from the original torque tube design. When you do this you may need to fabricate mounts for the brake and clutch pedals if you use a different bellhousing as they are mounted differently on later models. Later models also used different mounting points for rear motor/transmission mounts so you will need cross member from donor vehicle as well. If you do wind up with different height tire sizes front and rear make sure rear is taller per owners or service manual. My guess is this was due to the lack of rear main seal in original drive train but I don't know for sure.

Last edited by kb3csw; 11/14/2020 12:30 PM. Reason: thunk another thought