Update: Upon further inspection I discovered that my ignition is a Crane XR700. Also, my distributor has the model number D612-52. Research indicates that this distributor (D612-XX) was found on 70 to 73 cars.

So, it appears that I have a 'stock' distributor converted to an electronic ignition utilizing the Crane XR700.

I found the second adjustment nut as well. It was centered in the adjustment slot.

My next few steps will be:

1) Rotate the engine until the pulley shows 0 BTDC.

2) Check the cam lobes to make sure they are at the 11 and 1 position.

3) Check the position of the rotor.

4) Come back here and Zcar.com and do some more research.

I found the second adjustment nut as well. It was centered in the adjustment slot.

Seems like that should be the answer to your problem. Why bother with all the rest? Throw a timing light on it and set it to whatever you're looking for and call it a day.

Seems like that should be the answer to your problem. Why bother with all the rest? Throw a timing light on it and set it to whatever you're looking for and call it a day.

I have timed the car, which is why I know I am at 7 deg BTDC with the MAIN adjustment showing full advancement. The slot I found last night has maybe a third of the adjustment of the main slot.

The best I might be able to eek out is another 7 deg, putting myself at 14 deg BTDC for full advance on both slots. This would indicate to me that something is amiss.

I am not one to just let it be because the car runs.

Ok again, did you use the Haynes Manual for your firing order? If you did that's what your problem is. Go HERE and get the FSM for the proper firing order.

I have both a Haynes Manual and an FSM. My firing order is correct: 1-5-3-6-2-4.

Number #1 lead is pointing towards the radiator.