I understand the desire to escape CARB, but you would still have to smog it if and when you sold it.

I wouldn't cut up the '85 though, I would look for an IFS rig that is being parted out, similar to these, 1986 Toyota 4x4 22RET, parting out 86 toyota 4x4, Parting out 1988 toyota 4 runner, then throw a Dana 44 under the front. In the long run it would probably cost you less than what you could get for your '85.

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