Quote: Is it pinging? How are you telling it's at 45 total?
The motor will more then likely not ping even with 45 - 55 deg unless it is under a load. You get about that much advance when you have the vac advance hooked up... - you do not get pinging because the motor is not at WOT, when you go to WOT it takes the vac advance out and the motor is back to the mechanical advance. The more advance when the motor is under light load (cruse) is so you can run a leaner mixture and get better fuel econ. The leaner mixture takes more time to burn, so you need more advance.
