The JMAX is my beast!
The long n short of it is, that the 4jj1 will bolt up to any of the 4j-- engine mounts as they are essentially the same block with lots of mods to suit the common rail architecture.
Fitting the engine is the easy bit, gearbox selection is a little more difficult, but I ran with the dmax auto, as its the same type as the 4jx1 auto (and probably others too, yet its a little different).
The biggest part of the job is the wiring. You cannot get away with adapting it into any of the jackaroo/bighorn/trooper systems, and must replace the entire loom with one from a wreck. Also the looms are gearbox/driveline specific.
I'll put the writeup on here in another thread in the near future when I have some time. Happy to answer questions in the meantime