Wiring will be the biggest headache. I haven't read through the swap linked above, it might be there. If not there are few guys w/both the 7m and gte in trucks over on Marlin, that might be help, and I think some have done the swap on Pirate as well. You also have Supratrucks.com, that may be of some help.

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