Best replacement for distributor vacuum advance on a 2-bbl 1966 383?

Having seen ZERO function from the vacuum advance on my '66 2-bbl 383, I'm at a loss to find a replacement. PLENTY meant for FOUR barrel carburetors, but NADA for 2 barrel setups, be they Carter or Stromberg. Any suggestions? Or shall I just order up the new Cardone single point unit for about $90. I've seen NOS vacuum advance pots going for as much or more....... I LOVE my reman from Cardone via VatoZone, but I would love it more if the vacuum advance was working.