I use the 55-62 rear end because it has the 3.9 gear ratio giving you highway speeds or so. The spring perches need to be changed out and the leaf springs need either an adapter plate or remade entirely with the perch stud in the center of the leafs. Then of course a new driveshaft. This is all pretty easy for just about any full service shop. In Wichita, KS, Powerdrive makes the driveshaft, Atlas Spring and Axle makes brand new original style leaf springs and can weld the perches on if you cant do it yourself. Everything else is bolt up. Lots of people really like the R10 because it gives you essentially a 6 speed transmission. Good stuff! Pretty much exactly what bigbad said!
