Problem with trying to make over 400-450 HP with a small block is longevity. Many engine builders will state that they have small blocks making over 500 HP easy but they fail to say how many will with stand that level of over a t period of time. A friend of mine was running a 340 with 550 HP for about nine months before the engine was destyroyed beyond repair. Iron heads are my preferance for street duty, I have the eddy aluminum stuff with
TTI exhaust system on a 360 Duster, living in the high desert the car will shut down when parked and will not start until the engine cools to ambient temperature. The 340 duster with iron heads and 340 exhaust never experiences the same problems. Good luck with your build .
