Base timing Issues, while reving
 

hey i was wondering if maybe anyone know if the timing light supposed to move from 6* to like 12* when reved . Im thinking i got a vacuum leak. Base timing checking, not adavnce by computer.

what does everybody think, i want feedback. I got (TPI)MPFI, not a carb , or Tbi, crossfire,..but people with these engine let let me know your experience.