A 12H-T was designed to go into a 60 series, and it was only built for a couple of years. Great engine IMO, but not enough of them (or parts) worldwide to justify swapping it into a U.S. vehicle.
An 80 needs a 1HD-T or 1HD-FT IMO. I've seen some threads on MUD of folks swapping in those Isuzu diesels into 80s. I think a couple of them have finished and are driving them.
Rising Sun Bio
2F "Brahma" + Lockright, tach, Warn 8274, FJ60 Power Steering,
no more Sanden OBA
1FZ-FE factory lockers +
Safari intercooled turbo, CDL switch, cup holder, Metric TLC leather, heated seats, JDM switches, PUMA OBA.
Warn M12000 waiting for a bumper.
Limited TRD 2UZ-FE SOLD