find the ideal initial w the "vac gauge method" which includes reducing the idle sp (in drive/e brake on) back to "normal" which is where it'd b at a stoplight. Want 2 use front/pass port (ported) for vac adv. It may have a bit of vac at idle but not near enough to activate the can & that's correct but standard procedure you do cap it for the VG method. What is the lowest functioning idle speed you can achieve w your cam & that's the "normal" that you keep reducing it back to as you twist the dizzy w the above method