When cylinder one is TDC, the rotor should be pointing toward the front passenger tire, the distributor cap clips should parallel with the motor, and plug one tower should be furthest away from the engine block, right?
Yes. The rotor, when #1 is at TDC, should be directly beneath the tower that's connected to the spark plug for #1. Are you certain you have #1 at TDC of
the compression stroke when the rotor is directly underneath that tower?
Usually, when an engine backfires through the carb, the timing is way too far off to correct by moving the distributor. It's either 180 degrees out plus a little or correct but off by a little, because the plug is firing while the intake valve is still open.
At least you know you have ignition. If it's backfiring the fuel is igniting, which is a good sign. Don't give up now. You're close.
