8 1/4 to 8 3/4 rear diff swap

caferacer, i think you bought the 8 1/4 from me that i removed for the 8 3/4 it was in the car until the end of this summer. no issues and i checked the driveshaft freeplay. i dont have any high lift springs, stock height 6 leafs. from what i remember the driveshaft with the 8 1/4 had almost 1 1/2" of free play. i didnt take an exact measurement, beut i was counting on having to cut it for th e8 3/4. when i put the 8 3/4 in, it was damn close to 1". you dont need 1 1/2". you can get away with half that with no problem.