I was toying with the idea of a 1KD swap mate. What’s needed/involved in the swap?
a lot. changing from petrol to diesel is a lot of work. the whole fuel system, electricals, even brakes/ booster/ vacuum will have to be modified. as well as the usual, exhaust, engine mounts, radiator, engine management computer, possibly the sump, gearbox/transmission bell-housing & torque converter.
a 3rzfe from a later hilux may be a simpler option, but still a fair bit of work, or there are kits to fit holden v6 in, also require a fair bit of work, and a diff ratio upgrade, , a 1uz would also require a diff upgrade but have plenty of power and will keek everything all toyota,
here is a list of toyota engine which may be a viable alternative if you can make/ source parts required to make one fit
en.wikipedia.org