As a teen I drive a 60 with 12HT for a few months (on line from an uncle) it was heaps of fun, and started a turbo diesel obsession.
Later I had a HDJ81 with HD-T and tuned it up a bit.
It is a different to a 12HT. Smoother power delivery than 12HT. 12HT seem to be known for a harsh off idle throttle response, especially off road.
HDT doesn't have the same problem.
I also have a turboed HZJ105. The higher static compression ratio definitely gives you solid low RPM torque before and as the turbo kicks in.
In my HDJ81, 4.1 gearing with H151, and 35s worked pretty well on road, but gearing was too high for off road crawling
Later I had a HDJ81 with HD-T and tuned it up a bit.
It is a different to a 12HT. Smoother power delivery than 12HT. 12HT seem to be known for a harsh off idle throttle response, especially off road.
HDT doesn't have the same problem.
I also have a turboed HZJ105. The higher static compression ratio definitely gives you solid low RPM torque before and as the turbo kicks in.
In my HDJ81, 4.1 gearing with H151, and 35s worked pretty well on road, but gearing was too high for off road crawling