its the pressure differential of the volumeritic efficency of the etheric.....:laugh::laugh: any way on a stock engine it should be 18-19 in... tuned right..... at a hot idle...... 17 in.... would say '' possible vacume leak'' to me......
No need to disconnect the vacuum lines. Simply use a needle nose pliers and squeeze the lines closed one at a time and listen for a difference in idle quality. Doc`s suggestion re checking to make sure the butterflys are seating properly in the throttle bores is a good one. I had this chasing my tail for hours on a dual quad Buick once. Has someone rebuilt the carb recently? Also, if the engine has been rebuilt, it is possible someone does not have the crank and cam indexed properly? Is the engine low on power? I`ve come across this before also.....good luck, Tom Mooney
