Suggestions on coughing/stalling

1972 Newport.
Yesterday, I took a trip to the hardware store. Ran very smooth, except on the way back. Over the course of about 6 miles, it started coughing more and more. It almost acted like vapor lock, when I started it this morning, it was still having trouble so I don't believe that is it. It is erratic, coughs at idle and under load. It almost dies and then picks back up.
Just about all of the ignition parts have been replaced recently, so I believe it may be a lack of fuel. The timing...

Suggestions on coughing/stalling
Author: Jon O.