Steve that should be the ported vacuum. If you are getting Vacuum, there at Idle the throttle blades are a bit open. Also, to me 30 at idle is insane amount of initial when you add at least another 28 or so mechanical to it. then vac advance. Have a distributor number? Just for S&G check and see of you have a broken or MP spring in the distributor. Easiest check is to look down and see the springs, might have to rotate the dist. aka bump the engine and after that turn the rotor by hand and see how much resistance there is and if it will return by itself. Just spitballing here. If needed call me and we can go back and forth on the phone just easier.