<font color='#000000'>the infamous 3s-gte swap is what you're asking about, jhull will tell you everything you need to know about the swap for the fifth gen.
not so feasible to swap in a supra engine. although possible, it might be cheaper to just buy a supra intact:
1. not a cheap task
2. the supra engine is mounted longitudinally, the engine in your celi is mounted transversely, lots of work needs to be done to accomodate the 2jz
3. the supra engine's pretty big, you'd have to cut into the firewall of your celi to make it fit
4. not to mention, converting to rwd</font>
<font color='#000000'>That would be crazy cool, a RWD celi with a 2jz engine. *Drooling* <--they need a smiley for that....
But... I'd probably rather just go buy a supra if i had that money in the first place
<font color='#000000'>Something that will help you is bump your base timing to 16 degrees btdc. If you dont know how to get to base timing you have to jump TE1 and E1 in the DCL 1 diagonistics connector under the hood. I bumped mine to 16 and i just brought mine down for emissions testing and it feels like a turd. You gota bring the timing back down for emissions b/c adv. timing brings nox up</font>