Well its simple Look in the lower right-hand corner of the housing to find the cast-in number to tell you which one you have. If there is no number, then it is cast into the pinion support on the backside of the axle. or remove the housing and measure ring gear a 60 has 9.75 inch ring gear. As far a cutting they are pretty easy to make narrow for the fact there is no taper on the end of the shaft like a 9 inch. Or you could just order you rear end from dynatrac and they will do all the cutting and locker and gears for you. But that emptys your wallet really quick, take from one that knows.