I bought a 31-spline, positraction Ford 3rd member with 3.50 gears from a swap meet. The guy said that it was from a truck and that it was 9 and 3/8" across so I'd have to grind a 1/16" off each side of the housing to get it to fit in my Ford 9" housing. He said this was quite commonly done and that there are a bunch of videos on youtube showing you how to do this, but I can't find any. Has anyone ever done this? Did you have any issues with it? My axle is from a 1957 Ranchero and is currently non-posi with highway gears roughly 2.97's (they came with the car so I don't know exactly what they are).