Poor idle with vacuum adv plugged in, 1971 914-4 Frankenstein Options

[mikesjunk]

Ok so I've went back to basics to start going through things looking for the poor warm idle issue. I've read enough on the D-Jet to know this could be a challenge but it pretty much dies when you let off the gas to come to stops. Not so fun for drives.

So here's where I'm at
New plugs, wires, cap, rotor, condenser, points, intake gaskets, injector orings,
Carb Spray tested intake and all vacuum attachment points
Valves just set to .006
Dwell is 49 degrees
Timing is a tad over the 37 degrees. It bounces a few degrees from just out of the notch to right on....advanced side.
MPS does have small leak. It holds vacuum for about a minute....not the 5 minutes I've seen in specs.

So when I was checking the timing I had the two vacuum lines from the distributor unplugged and capped. Got it checked and went to plug in the one on the front of the distributor that points back at the distributor. As soon as I plug it in the idle drops a couple hundred RPM. It idles much better unplugged even sucking air.

So any clues as to what's next. Not sure I've seen/read what the two ports each do on this distributor.