440 hp super commando carb

[268gtx]

hi all, I would like to find out what cfm carb would have been on this 1968 440 hp super commando 4 speed in a plymouth gtx. when i bought the engine it had a edelbrock intake with a holly on it. I had motor rebuilt put stock intake back on and hp exhaust manifolds. some people tell me to buy a 600cfm edelbrock and others say 750 cfm. does anyone have a 1968 afb "mechanical secondaries" or tell me what carb from edelbrock has mechanical secondaries. also all afb carbs are mechanical secondaries right?

[John Kunkel]

The '68 440HP was equipped with a Carter AVS carb. Most sources claim that the factory 440 AVS was 750 cfm but the factory rated them at more like 635 cfm. A 625 Edelbrock would be a good choice, be sure to get the correct Mopar throttle lever extension for it (#1481).

All of the Carter AFB's and AVS's have mechanical secondaries as does the Edelbrock but most models have air doors above the butterflies that limit the initial airflow so the airflow isn't instantaneous like a Holley double-pumper.