[JMFL36]

Well, my setup - original 54 Merc distributor and vacuum advance with vacuum supplied from intake manifold, and 54 Lincoln Holley 891 carburetor with vacuum port plugged, seems to work ok. But this may explain the initial slight stumble I get when accelerating (under load). It evens out after a second or two, which could be from the temporary drop in vacuum when accelerating. Make sense?