I think the answer is pretty simple - 3rz    I bought a running t100 to stick the 3rz in my 80 but opted to use a low budget 20r I already had sitting around until I can get everything to stick my buick v6 in there.  I don't like half assing or setting myself up to get stranded, so I put it back together with toyota parts and may as well have just spent the extra money and gone with the conversion    I definately wasn't looking forward to the wiring involved in swapping in the 3rz either though!