have a 30 over 454, 9.5:1, ported 781's 2.19-1.88, torquer II intake, 750 holley, 553/528 302/308 cam. I have 2 distributors , a mild performance hei and a mallory magnetic breakerless (no vacuum advance) which do you think I should use?

Assuming that they're both in good condition, I'd go with the HEI just because of the vacuum advance. If it hasn't already been done, I'd recurve it to bring total all in much sooner than stock. Depending on the rest of the combination, by 2200 -3000 rpm.