Count and measure the mounting bolts...also, check the axle spline count when you pull the axles...as long as they are all the same it should work.
I did the same thing on my fire truck (Eaton Rears) and the only mod I had to make was the grind a notch in the bolt flange of the housing to allow the taller ring rear to slide into the housing...easy.
Make two long studs out of concrete "L" bolts as guides about 12-16" long to aid in lining the third member up with the housing while rolling it in with the floor jack, this also keeps the gasket in place.
Mike B
