[DeTomaso] vacuum advance

[dennis617 at aol.com]

So I just got my new replacement vacuum advance for my Mallory Unilite distributor and it appears that the advance I'm getting at full manifold vacuum is way too high, around 24-25 degrees (plus the initial 16 degrees for a total of 40-41 degrees at full vacuum).  Does anyone know what the total vacuum advance is supposed to give so I can adjust it, at least for a starting point.  Right now she is backfiring all over the place.