FINALLY - Vacuum Advance Dilemma Solved

[DAVID GAGNARD]

Originally Posted by WardL

I have mechanical secondaries and advance. I get too much bucking at low speeds. What I'm hearing from this debate is the mechanical secondaries are probably ok for me on the street, but I could improve the low speed driveability with a vacuum advance set up. Would I need a completely new distributor to convert to a vac advance? I can probably get some kind of conversion kit from MSD. I have a Bigs Stage 5 modified Holley DP. Sure knows how to suck gas! I'm a dummy so go easy on me....

An easy way to tune a holley weather it is vac sec or double pumper is:
get the engine fully warmed up and put a vacum gauge on it and begin turing your idle mixture screws in or out and watch the vacum gauge, your looking of for the highest reading possible, do one screw at a time, when you get the highest reading, move to the next one, you'll have to re-adjust your idle speed and you'll have to go around the carb 2 or 3 times to get it to the highest point, then take it out on the road for a test run.........this is also assuming your timing is correctly set from the get go.......
Not sure if you can add vacum advance to a mechanical distributor using an MSD distibutor, you could call the MSD tech line and ask.....

David