Yes, it works. I also checked for true TDC with a dial gauge, checked the vacuum advance with a big syringe, and it moves and stays until the vacuum is released. When I was fooling around with the timing at idle, the idle speed would keep rising as I raised the timing, up to about 18 degrees, but I just chickened out and left it at 12 degrees. I was going to try the whole business of adding advance until the engine pinged and then backing it off slightly, but I thought that 12 degrees was enough!
