I'm running a stock 67-383 non hp with a Mopar Performance electronic dizzy and a GM ignition module conversion with 50kv coil and .042 spark gap. I'm tuning everything again after rebuilding my 1806 carb and I've run into an issue with timing. With the vacuum advance hooked up and the initial timing set to 12.5ºBTC my max timing is upwards of 50ºBTC...way too much (checking in park in the driveway). If I disconnect the vac advance my max settles in about 36º. Is my VA bad? Sticking? Can it be adjusted down? It's my understanding that it should not add to the total timing because it will drop out once manifold vacuum drops at high RPM. Someone suggested that it may be sticking and still adding to the timing. Checking it with a vac pump it adds a total of 15º.....36º+15º= 51º...which is what I'm getting with it connected. With the VA disconnected and the line plugged the car runs awesome...even at part throttle. Good response and power. Throw it back in and its not nearly as good.