...which, of course on a stock engine is too big. My '79 ran with the early 780 cfm version of the 3310 on a 10,000 mile cross country trip and it went from poor gas mileage to beyond horrible:CRY::CRY:. I had several different Holleys on after that, but what ran the best - a 600cfm Edelbrock. I would probably opt for the 650 they sell now instead.