I currently daily drive a 260z with a 2JZ in stock form, and haven't even built an exhaust yet. Probably running 2.25 exhaust, with DP Cat, another shittier honda cat, resonator, and muffer. I'll tell you right now, that even with GOOD sticky tires and a damn good driver, this car is a handful even with stock twins. I may be putting down....250ish wheel right now, and its insane. Sure, build a car with 500 HP, but if you accidently fall into the boost range on a rainy day, thats going to be all she wrote lol. I'd say go the route I'm going. I'm going to keep it stock, boost it to 16-18 lb's, build a nice exhaust, and pickup an LSD and call it a day. Should be more than enough.