Am laughing at the debate on built motors vs stock de/det, REALLY? We sare STILL discusing it like its even a issue? If its a det, and your tuned right, it will take some SERIOUS hp to destroy it. even with a de, id doubt it would have a problem making 450hp on stock int, as long as you used meth. i dont know how a gt35 would do on the street, especially on a stock de/det head. I would think very LAGGY. With a vvl head and equal length id imagine a gt35 would be pretty decent. Can we consider a vvl head? Jeong, fwd equal length twin scroll manifolds are now available, setup for evo turbos! get a fp red, this manifold/downpipe combo i mentioned, and throw in a vvl head and b15 trans on a det.....shoot for 500, lol. If your going to do it, DO IT. By the way, david has a evo 9 now with a fp red, and a decent "Trey" tune. That thing is NOT laggy by any means, get him to take you for a drive in it. NASTY. id imagine as the bore/stroke of the 4g63 motor is the same as a sr20det, that similar mods to the fwd sr chassis will net the same results.
I honestly think if you went the "evo turbo" route, youd have a damn good chance of making your goals with a stock evo 9 turbo. just my opinions/build ideas/rambling. AND it seems you can run stock size radiator and fans.....ill have to go back and double check.