Need Dual Point Assistance

So I had Halifax rebuild the distrubutor for me. Definetly pleased with his work! It had a few issues (bent shaft and worn bushings to name a few). Those issues are taken care of, but it still has one issue that neither of us can figure out.

I electrically checked out everything yesterday, before and after applying vacuum to the vacuum advance (via a handheld pump). There was no difference before/after when checking the wire, or continuity through the vacuum plate itself.

When I apply vacuum to the vacuum advance, the car starts dying. Has anyone experienced anything like this?
My carb only has a carb vacuum port:

Idle: 700 1000 1300 1800 2200
Carb Vacuum: 0 6 14 18 22
Vacuum starts dropping off after 2300 rpm
^Won't let me line those numbers up, but the 700 goes with 0, 1000 with 6, ....

Just thought of this, are you using a paper gasket on the distrib or a metal one it should be metal so the ground is good.

Like this one.

The clamp will give it a good ground unless heavy paint

bm02tj said:

The clamp will give it a good ground unless heavy paint

Click to expand...

Probably better than the steel.

I have seen some funky things with dual points missing a consistent ground.