I just installed the pertronix unit on my 69 280se coupe. I grinded the vacum advance bracket until it cleared the magnetic ring. then installed and connected the wires. Fired up imediately. Idle was low though so figured the timing had changed grabbed the gun and proceded to check the timing. It looked like the timing wouldnt advance i was really bummed. I then noticed that the petronic plate has a notch in it on the edge about a 3/8 or so long just below kinda behind the pickup. This notch seems to coincide with a tab from the distributor plate. it seems to me that this tab is holding the plate from advance as on the points it didnt have contact with that tab.
Has anyone else run into this problem. or am i barking up the wron tree.