O.K. Denny, that settles it---I will use the port which you pointed out in the marked up picture for the port to run my HEI vacuum advance. I will use the small port at the rear of the carb beside the power brake vacuum port to supply vacuum to the transmission modulator valve, and I think that I will use the vacuum brake port to supply vacuum to a pcv valve from the passenger side valve cover. Thanks a million guys, I,m going out to the garage now to install the carb.