[Dave at Pelican Parts]

Remember that all of the stock (FI) distributors have a vaccuum retard function.

When you have the engine shut off, the springs in the distributor take out all of the centrifugal advance. There is also no vaccuum on either the advance or retard ports on the distributor dashpot. But if you applied a vaccuum to the retard port, the points plate should move in the "retard" direction. Which means that there should be some "slop" in that direction when the engine is off.

--DD