I have fitted a 35,36 10 spline 3.54 in a 34 many moons ago. The top of the pinion gear teeth have to be ground down to clear the scalloped opening of the banjo.Then the pinion bearing surface has to be ground down to the dia of the 34 pinion bearing and double cone. The pinion is overall longer so you have to shorten the driveshaft accordingly. Sounds complicated but its not.