Doug Have you considered a pair of 390CFM Holly's. With what you going to do, they might work for you. I was going to put them on my 305 which was bored .060 over with a mod. cam, etc. but I went with a 600CFM edelbrock carb and dual plane manifold. I am now going to put 3 dueces on it and just run the center one until I kick it to WOT and then the other two will kick in.