na the GM 4.3 5.7 diesels are by far worse
the 6.2 with the newer B head setup does ok if
(no) turbo.
turbo a 6.2L and you have a ((very high)) risk setup. even in a little LUV or pup.
though 130HP in a little LUV with 250+tourqe getting the same mpg as the 1.8 gaser woudent be that bad.
if the frame and aixels can handel it.
if your guna go thru the trubble of beffing the frame and aixels the cummens 3.9 I-4 would be a better way to go. though more $$$$$$ to do. but LBs 550ish for the 3.9 i think its a little less LBs than a 6.2L or 6.5L engine.
it can be done ether way but its a big project.
one of thoese inported 2.8 3.1 isuzu diesels would be a much esear install, no body lift. though $3,000ish for the engine trans and there all 4x4 that i have seen. same power as a 6.2 from a 2.8 or 3.1 engine stock.