If you want power AND reliability build an NA car, absofreakinlutely. I made 411 RWHP out of my LT1 with a 234/246 cam, and of course ported heads yada yada. I made that power about 600RPM short of where I should have peaked, due to an ignition miss. That was with shorty headers, even with shorties it was supposed to hit 425/430 RWHP, stock bottom end.
Its not 450, but with a bigger cam and such a light car it should not be a problem, I had stock rear gears with that car as well. If you want dead on reliable there is no question in my mind that NA is the way to go.
As a road racer, even in a 3400 pound car (approximitely), I can tell you that the car will be ******* undriveable, especially if you end up weighing in at 2300 pounds. It takes a serious driver to take corners in that thing, I could be WOT for about 3 seconds in that car at Thunderhill. When being a little too fiesty, I went sideways into the dirt at about 120 MPH. If you truly want to race the car, be reasonable, and make it a 13/14 second car, and build up HP later on. Once you hit the track, you will find you wont have to slow down as much as heavier cars in the corners, and you will run rings around many of the other cars. Get some rubber and brakes on there, springs/shocks, and voila.