A 1406 is a 600 CFM carb. I'd suggest a Holley 390, a Quick Fuel 450, or an AVS2 500. I'm running the latter and it works great in the truck.?
I own 2 1406 Edelbrock carbs. Wouldn’t this be a good option for the 4bbl/header setup? 450cfm if I’m not mistaken.