I have a 71 455 in my 69 GTO with KB pistons and all I had was a 600 edel at the time which I thought made it run good. This year I picked up a 750 edel. So after putting that on it made it feel and react like it had 2 more cylinders. I could have probably gone bigger. Sounds like it may be a fast car there Chevygirl. But that is alot of carb to be dealing with. Good luck and have fun with it.