Have you come across this 22r3-7m Swap write-up on Yotatech.com? The first post has links to two other write-ups. This Wiring break down may be helpful.

Here are a few more links that I have found.
Rockymountainextreme.com
BC4x4.com
Wildyoats.com

I haven't read through them all, just collected them for info for if/when I get around to doing the swap in my '91, that is if I ever get done with my '87 Supra turbo resto-mod build-up.

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