With great power comes great responsibility - not sure if I said it right or not lol
The thing is that ive driven UZ with a manual tranny and with an auto too. My PG supervisor has got a pajero 3dr with a 2nd gen UZ and damn that things quite torque'y but its auto. A friend has a KS13 with manual UZ but never liked the shifting response, oh yes if some one has deep pockets and wishes to mate a v160/161 to it then its fine i would say. Even W series are weak for that Nm transmission.
But as your looking for torque, things wont be easy as sucking torque from an engine is not a big deal, but delivering that to the wheels and road is of major concern. Cress has a long wheel base and you'll be swinging all the way down to the next signal dragging that 1.5 ton frame along. For better traction you'd be needing an independent rear sub that wont be bolt on to the chassis, you'll need to fab the floor. If you wish to get jzx frame then look for the oem 2pc shaft aswell cuz it would fit easy peasy with W box and find a good fabricator to mount it. Looking forward to updates