Rotor Phasing

That might be OK if the vacuum advance will move it towards the tower as it comes on. You can connect a Mighty-Mite hand vac to easily test that. Note that vacuum advance moves the phasing, whereas the centrifugal advance doesn't since that angular shift occurs below the reluctor wheel pickup.

Sounds like the 91 Magnum engines still used a distributor for spark timing vs later ones which use a crank pickup and computer. But I am surprised they still used a mechanical pod for vacuum advance since my 1982 Aries had that in the "spark computer". Perhaps you are using a 1970's Mopar distributor.