Did you drop the pinion down yet?, it should take either a 2-3* shim. 2-3* doesn't seem like much of a difference, but it is enough to cause premature wear/failure of the u-joints.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed