Super Runner
Your idea has of the 2JZ-GTE in a 4x4 T4R has been a long time dream of mine. I have found a few videos on the net of a Supra powered 1993 T4R. It had (I think) Dana axles (SAS in the front) and what looked like 38 inch TSLs. I dont know the gearing, trans, or t-case arrangements, or even motor fitments though.
The gear ratios in the 6-speed Getrag transmission would be great for a 'wheeler as well:
1st: 3.827
2nd: 2.360
3rd: 1.685
4th: 1.312
5th: 1.000
6th: 0.793
A divorce mounted T-case would be a must. Inchworm Gear sells a divorce adapter for Toyota T-cases. It could be hung between the frame rails with a Front Range Off Road style t-case crossmember.
With all of this, three new drive shafts must be made: front, rear, and a very short jackshaft between the trans and T-case. 1350 series joints would probably be beneficial, considering the stock 2JZ puts out 325 hp and 315 lb/ft of torque. Tom Woods or High-Angle drive line can fix one up here.
The next problem would be fitment of the rather long and tall, but reletively light (for and iron block) engine, radiator, AND intercooler(s). I have seen everything from cut firewalls to radiators being mounted on the roof (BB Olds 455!) to make an American engine fit in a Toyota truck. Just be imaginative!
A single turbo swap would eliminate most of the unsightly and confusing vacuum hoses and make for way more room in between the fenderwells. Swapping all of the wiring would also be a pain, so maybe a stand alone type fuel system from GReddy (not sure if it is still available) or APEXi would be easier.
But how stinkin' cool would that be?! Check out the drawing I did in MS Paint about 1.5 years ago. Maybe after I get out of college....