The 7m should be torn down and rebuilt, unless it has very few miles on it, so you should have time to look for a cheap rebuildable, rig for your 22re, if you can't find anyone willing to pay what you want for it. Might also talk to a buddy and split the cost of the rebuild, i.e. he buys the rig you supply the engine, split the profits.

You wont reuse the 22re's ecu, or much of the engine side wiring harness, so make sure to get the wiring harness and ecu w/the 7m.

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