What is the correct amount of vacumn advance?

Hey guys Thanks for all of your reponses. I have been fighting a stumble right off the line. First I thought it was fuel. After replacing the carb I still had the same problem. I then that carb gone thru by one of the local carb experts to check it for problems. None found. I then added a jetplate , notched float and jet extensions. I had one last trip to the strip to check it out. Better but still there along with fuel stravation on the big end. Currently I am replaceing the whole fuel system. New tank, 3/8 pick up, 3/8 line and carter strip fuel pump to feed the Holley 750 vac secondary. My times have been disappionting to me. I know the car should run faster. I wonder now with my timing being set at around 36 total with vac advance hooked up is my problem. My new tank came in today so I can finish it up and get it running again. Of course we are supposed to get another 6" of new snow tonight. Snow is better than NO electricity. We lost it for a week due to an ice storm.
Thanks Again Guys. Jeff