I have a 86 with a sterling 10.25. It has a bad pinion seal. I bought a sterling 10.25 out of a 1995 ford f250. I bought it because of the long pinion. When I went down to the axle shop the guy told me that I shouldn't have a problem with the u joint but my driveline would need to be shortened. I don't understand why. Both axles are sterling 10.25's. As far as I can understand the splines are a 1/2 " longer on the long pinion and the pinion yoke is also 1/2" longer. Does 1" make enough difference so I have to shorten the drive line?. I'm just a hobby mechanic, so I have no prior axle or driveline experience. I'm probably wrong but I was hoping to just swap the axle in. Any and all advice is appreciated, thanks.