Last week i bought a 9 inch from an 81 F150. It is 31 spline. I have seen 35 spline Powertrax No-Slips, and i have to get Moser to custom make me some shafts anyway to accomidate for the bolt pattern difference, so do i just throw 35 spline shafts in there? I have been searching this and both the 31 and 35 spline are 1.5 inch shafts, so i don't think that i would have to do anything to the housing. I could be wrong...anybody know.