Just remember there's three types of HD motors. I was referring to the DT, the FT and FTE motors are far superior and don't have the design flaws of the DT. Pretty common these days for people to swap out their DT for a FT/FTE as no one wants them anymore. I even know a few people going from the DT to a turbo HZ and are much happier with the performace and reliability. The H150/H151 boxes have a fragile third gear arrangement which fails often to go along with the terrible syncros and gear changes. The RE4 is a dream to use in comparison with its smoother shifting and is much stronger. I blew two rear diffs and was considering doing a patrol axle swap which is becoming quite popular as it also gets rid of the other weakness with the weak axle/hub studs. I can't think of anything on the cruiser running gear that I'd rather have compared to a patrol.
The difference between 1hd-t and 1hd-ft is only the head, the latter of which has 24 valves rather than 12 valves, and hence more powerful.
1hd-Fte is electronically controlled fuel injection version of 1hd-ft, which is used in later landcruiser 100, hence the "e".
My friend had a 1hd-t, and later on he put a ft head on it.
You can't go too much boost on a 1hz engine even if you put a turbo on it to make it like a 1hd-t. It is not like td42 and td42t, totally different things, being direct injection (1hd-t) and indirect injection(1hz).