Dual Quad 389

I asked around for a long time for info on what carbs to run on a dual quad set up. I found out that not many people have done dual quads on old motors.

I'm using matching numbers 1965 Pontiac Carter AFB 550 CFM carbs.

The best info I got was to use the same carbs and preferably the same make as the vehicle they are going on.

Those are great carbs to run on a dual quad setup! The mistake most people make is that they go too big. You're pushing 1100 CFM as it is! I'm assuming that you're running them in parallel as opposed to one at idle and both at WOT. I've never really had a reason to run more than a single 4bbl.

I was going to set them up progressively. So cruising it'll just be running on primaries on the primary carb. At WOT all barrels will be dumping gas and air!

Dual 550s does seem like a lot but I think Buick used dual 625s on their factory dual quads and I think Pontiac did dual 600s. Please correct me if I'm wrong. I finally gave up on getting advice and decided to give what I have a try.

where did you find a manifold? I have seen the tri-powers but have not seen any 4 bbl manifolds.

I got my dual quad manifold on ebay. It's made by Offenhauser. There are not many '59 OEM cast iron 4 barrel manifolds around but they do exist. Keep your eyes open.