2JZ in a Hachi, What about RB26DETT?

[NoHachi]

Ok, no hard feelings. No offence intended from me either.

To get this little thread back on topic:

Putting such an engine in a AE86 still isn't going to be easy (if it fits). Its not so much the horsepower, but the torque that the engine puts out. The extra torque will soon destroy your diff, but I'm guessing you already planned on using the some other sort of rear end (toyota pickup or something like that). If you can get the pumpkin to stay in place then the torque is transferred to the unibody. I have seen cars tear welds through (though it was on a honda CRX, destroyed the front subframe+mounts).
Be aware that cars are usually designed using the "engineering margin". Basically that means that the engineers at the factory calculated the force that is put on a part and then design the part with a margin of 2 (two times as strong as needed). When you approach the margin on a car that has already been put through a lot of fatigue cycles strange things can happen. Sadly fatigue failures are sudden and unpredictable.

The engine is a lot heavier than the 4A-GE, so you should ideally upgrade the braking capacity to suit (not just pads, but a physically larger system that can soak up the extra heat). The weight balance of the car will shift further up front, so plan on a brake bias valve and a custom set of springs.

When you adress al of these points (and some more I didn't mention) you will have one hell of a monster of a car, but you could start with any other car and have the same result.

Another suggestion that may annoy some the JDM lovers out there: Take a look at the Rover V8. Its the same engine as some sort of american V8 so there is massive aftermarket support. The difference with the US engine is that the Rover V8 is all alloy. That means this V8 is actually a little lighter than the standard iron 4A-GE. New engines are available from the UK putting out 300 bhp NA. Lots more to be had from forced induction and a lot cheaper than with JDM parts. Basically up to 2000+ hp in methanol burning drag racing application is possible (and has been done before). You'd have the same HP (and same problems that come with it), but a better overall balance in the car and a lot less weight.