[sedanbob]

My turn-key ZZ4 crate motor came with a Holley 750cfm dual-feed, with vac secondaries. Some guys on another forum think that is too big for a ZZ4 on the street, and recommend a 600cfm instead, claiming it will be more responsive and still deliver power. I believe they are thinking about a double pumper. When I suggest that I am mostly running on the primaries, and the vac secondaries will open as required at higher rpms, I don't get any answers.

Does anybody here know what the cfm flow of just the primaries might be? I have searched all sorts of Holley specs, but can't find this particular spec. The engine seems very responsive to me, with no lags when I put my foot in it. The newer ZZ4s now come with a 770cfm Holley.