Edelbrock AVS2 Carb Dilemma

In high gear your effective rear axle ratio is 2.29 to 1. By your description of mostly cruising highway car with occasional quick romp to 5500, I’d go with 500 cfm and get a little better mileage. Those runners go down to 318 ports at the exit, but that’s one of the better manifolds for a 318. I’m sure the engine would run with the 650 better if the car had lower gears and a close ratio transmission, but the 500 will help out the lower rpm with the wide ratio spread of the OD transmission. Following the rules of Rusty’s guide to hot rod bliss on this one. Either way, the engine will only pull as much air as the secondary air door spring tension will allow. May as well keep the primaries as small as possible for cruising with a combination that mild