I have a 1978 P/U with a 305, Crane medium cam, Hooker headers mounted to Thrush Turbo mufflers, Weiand high rise manifold and, currently, a Holley
600 4 barrel, manual choke & vacuum secondaries circa 1990 or 91. It's been sitting up and the front seal is leaking on the Holley. Before I go either rebuild or buy a new one, is there a better 4 barrel to go with? I was looking for a little more pep than I seemed to get from the 600 anyhow. I have had suggestions to either go to either a 600 double pumper or a 650. Or possibly go with a 600 with mechanical secondaries? Gas mileage will not be a problem to worry about, just so I get good performance. Thanks in advance.