Fuzzy Math

I’ve typed this so many times lately I’ve worn out the keys on my keyboard.

Buy your carb based on venturi diameter and NOT CFM. Carb manufacturers think we end users are so stupid that they use CFM so it’s simple. But it’s a piss poor way to size a carb.

Without typing out 40 pages, the upshot is all 4 venturi carbs are tested at 20.4 inches of water. There isn’t an engine out there that pulls that kind of average depression.

For a relatively stock or a “warm” small block you should have a 1.250-1.310 Venturi and 1.688 throttle blades. That’s all you need, unless you want to use annular boosters and tune for that.

You’ll have the best drivability, the lowest fuel consumption with that architecture and still have plenty of air at WOT.