My engine is a 302 roller rocker with flamethrower coil and pertronix billet distributor. The car idles around fine but when I get on it there is a popping sound small pops at 2000 rpm and beyond and wants to stall. I checked vacuum with a gauge and she's steady as a rock at 19/ 500 mm Hg. So no sticky valves or vacuum leaks or similar problems. The carburetor is a Holley 650 double pumper that was very recently rebuilt. Could it be carburetor troubles? Blown power valve? I am considering getting a new Holley 650 with all the technology built into it. Or is there some other problem? Any suggestions welcome. Thanks, Richard E.