I just installed a Petronix sender in my '72, and I can't find my timing marks either on the damper pulley or the flywheel. The car was running well before the conversion, so I adjusted the distributor so the rpms is the same and it continues to run well, but I can't find any of the marks described in the Haynes manual.
I hooked my stobe light to the front cylinder. Could that be part of the problem?