[RichardJ]

To keep this Chevy related, the spec sheet with the rebuild kit for this carb shows that it was used on 1966 Chevrolet 327's. It was also used on 307, 327 and 350 Chevy Marine engines.
The Mopar 440 AVS had 1 11/16" primary and secondary bores. The 383, 340 carbs had smaller 1 7/16" primary bores. Depends on who you believe, but many list them as 625 and 750 cfm carbs. Edelbrock's cheap copies are listed as 500, 650 and 800. They don't list the bore or venturi sizes so I don't know how they compare.
The one with the smaller primary and the flow regulated secondary does not have a problem with a 300 cu in engine from what I've seen. The secondary only flows as much air as the engine can handle.