[Formulajones]

You dont set your total timing with vacuum hooked up.

What tom and others are trying to explain when doing that is rev the engine until all advance is done and set timing at your total, without vacuum advance. This assures that total timing under wide open throttle doesn't exceed a certain number you're after. Vacuum advance is inop under wide open throttle so it's not a player here.

Most likely 38-39 will be too high for total mechanical timing in a pump gas deal like yours. You may end up more in the 32-34 range.

Only after this is set properly will the vacuum advance be hooked up and dialed in, on top of you total. Usually end up with maybe 10-12 degrees additional that should put you around 44-46 degrees which is only in play at light throttle cruising. With that done your initial should be somewhere around 12 degrees if the distributor is set up properly.

You likely won't come close to hitting these numbers or anything resembling these numbers without modifying the breaker plate and welding things as cliff mentioned.

For this I'd recommend you send the distributor out to a qualified individual.