Per Holleys website a 4777-2 (650DP) has a 67 in the primaries & a 76 in the secondaries.. Jet size isn't the whole picture, air bleed can cause a smaller jet to flow more fuel than a larger jet with a differeenr air bleed... The factory jetting on a DP tends to be rich as it is intended as a "offroad" part... By leaning the primary jets you clean up the idle & light cruise circuts but if you don't alter the PVCR the carb will be to lean under power... FWIW I'm not trying to sell anything & you can jet anyway that suits you...