Actually not to be a nit picker, but all (wow, like 3 lol) truck 305 carbs I've looked at are 800CFM units. Nothing to brag about though, that hurts your MPG, (compared to a 750)and on a 305, the engine will never demand 800CFM. (I'm using 800, easier to type than 795 lol)
However, the one I had on my '83 ran like a champ after I rebuilt it, and gave me an all-time high for that truck of 17MPG.
Oh yeah, forgot. By the late 70's, GM was mechanically limiting the secondaries of these carbs to an estimated 650 or so CFM, and if you compare different years/applications, the "limit tang" on the secondary air valve shaft (passenger side top) got longer and longer.