here is the back ground. SBC 327 Rochester quadrajet. (stock spread bore). Edlebrock perfomer intake HEi ignition. comp cam 12-242-2 if you need more info let me know while at Idle engine has about 14 to 15 inches Hg. vacuum the needle vibrates somewhere between 13 and 14 Hg consitantly..like a buzz so fast that the needle is a blurr. at acceleration the needle keeps the same blurr. and while holding the RPM at say 2000 or 2200 or any other elevated RPM the needle continues to keep that blurr or vibration. also to add to the equation at the elevated RPM there is a uneavenness to the engine, like a stumble. Tonight i plan on changing the spark plugs, and the carb base gasket to see if this solves or changes anything. anyone out there ever have this type of senario before? what was your diagnosis? what changed things. should i worry about the rapid needle vibration its only 1" and focus more on the engine stumble? yes i have gone thru and adjusted and re adjusted the valves , it doesnt remove the 1" needle fluxuation.