I think nissan managed to squeeze up to 80 Hp out of their diesels by the mid 80s in their compact pickups. Quite a feat considering no turbo on them.
I know next to nothing about the isuzu/luv series though.
Diesels through out the mid 80s were all the rage before the EPA cracked down in 1987.
Ford had the tempo, ******, LTD, and lincoln continental (I think) along with the rangers and F/E series trucks.
Makes me wonder what could have been but the EPA and CARB show little signs of slowing down.