Timing Problem

I dropped a rebuilt 360 into my 73 charger. For some reason, I can not get it timed. I followed the instructions to set the #1 on the distributor in line with the front drivers side corner where the intake and header meet.

I've warmed up the car and have the idle set. When I look at the timing, it is above 10 BTDC. When I turn the distributor so that the timing is at 10 BTDC, the car runs rough and bogs down,

Could the distributor be one tooth off and still run as good as it does? It starts right up and runs smooth if I don't set the timing at 10 BTDC.