Vac adv capped then bump the initial up to 18-20 & slow the idle speed down as low as you can get it to idle decently. Then plug the vac adv in to a ported carb port & hopefully the throttle blades are now closed enough to where the ported port you are using has no vac at idle. On the dist with a vac pump (eng off) pump up the vac can gradually & at the vac level where the gap is the narrowest set the reluctor gap at .008". check rotor phasing. After bumping the initial up check (& post) the total & ~38 (checked with vac adv capped) is in the ballpark. That'd be a start. EDIT What springs are in the dist?