The 1UZ has been done. They take the A340E 2wd automatic transmission that came with the 1UZ and swap in the tail and transfer case from an A340F. Unfortunately, you have the A340H which does you no good at all. Then you've got all the wiring to consider, much of which will have to be run custom in order to intregrate the 1UZ computer with your dash and body harnesses. And don't forget custom motor mounts and a transmission/tcase crossmember.
It doesn't drop in, it's pretty much a complete drivetrain replacement. By the time you've done all that work, you might as well have gone with an LS in the first place. Unless you have a 1UZ sitting in your garage waiting for somewhere to go, I'd skip it.