Hey guys, I have a SBC 350 bored .040 Professional Products airgap style intake manifold, Holley 750 double pumper, and Patriot 64cc alum. heads. Roller cam/lifter/rockers. Now the question when tuning the carb, using a vaccuum gauge I use the fully ported inlet/outlet on the front of the carb. When I pull the cap off of the stem the engine increases rpms slightly and smooths out instead of running rougher like any other vaccuum leak. What if anything does this tell you? The engine pulls 17.5" at idle (720 rpms) This engine runs great, I just think there might be a little more in there.

Thanks