the nipple on the pass side of the carb on the metering block would be ported vac for the dist. Manifold vac (if desired) would be a nipple at the base of the carb (front side on a Holley I believe) & there might be an additional inline in series valve that regulated the vacuum from the carb to the dist. Seperately full vacuum would go to a switch/valve of some sort then to the EGR pod there on the dr side. I would leave it as is unless you need it operational for emissions testing or wanting everything to be OE appearing.