maybe the stock computers on the 2RZ and 5VZ handle timing under boost better? i'm not sure...

would the stock ECU be up to the task of handling say, 6lbs of boost? low compression pistons would definitely be on the list. funny you listed the 3 core radiator as being important, as i just installed one last week(the original was cracked, and the 3 core was only $5 more or something from radiator barn)

what i'm dreaming over is having something mild to drive to work every day, but having that ability to drop a gear, spool that turbo and be able to have a little more of a fighting chance at the passes, or when towing my little boat, etc