The carb is in dire need of replacing but I was waiting until I put a new intake on and convert from 2 bbl to a 4 bbl. I would not be surprised if it is a carburetor issue. I guess it wouldn't hurt to replace the pump but that is not that old
Gas cap... good point. I w as s dio g body work on that quarter panel and haven't put the cap back on. But that has been off for a while and didn't seem to affect it running. I will put it back on just in case
My thought was if you put a non vented cap on and it requires a vented one. Having the cap off says it's not the fuel tank venting.
There are many easy tests you can do.
You can run a hose off the fuel filter into a can, prime the carb and start the engine see if you have flow from your fuel pump through the filter.
USE ALL SAFETY PRECAUTIONS WHEN WORKING WITH OPEN FUEL.
Put a "T" in the fuel line to the carb and see what fuel pressure you have while it is running
How long has the fuel in the tank been sitting with the cap off? You might have absorbed an excessive amount of water in your tank. Gas is lighter than water so you might be sucking water into your carb.