buddy of mine has a 99 stepside reg cab with a 5.3, 4x4, 183,xxx mileage. his tranny is going, and he is wondering how hard the swap would be, he knows its not a bolt and go, but besides the computer and the crossmember, would it be terribly difficult?

he also knows that he would need another 4x4 one.

hes a mechanic for the army, so hes fairly savvy on mechanical stuff.