Constant or Ported Vacuum Source for Distributors? ...AGAIN!

Crap shoot on any of them. I usually spray a bit of armorall in them when I put them on. So far so good. These are a real PIA to find NOS any age. Really wish someone would re pop them. I hace had a few BWD fail the vac test with pinholes I guess or cracks in the rubber diaphragm and you cannot return them. The worst ones I have dealt with are the HP mopar ones with the electric retard, Two times I am aware of guys spent 250+ on them nos and they were bad, I hate those things. They can even bench check and a week later the retard part fails! I try not to deal with them at all.