Right now the advance is hooked up to the carb. It was mostly a stock build with a mild cam. Fan and shroud clearance is good. No fan clutch. From what I can tell it only takes place while I drive. I haven't had it just sit idle long enough to see. One other problem I have is that the car runs terrible when the vacuum advance is hooked up and I can not get it to idle no matter what. The car does run once it is unhooked and just lying thier. What could this mean?