'66 c-10 starting issues

[bigchad64]

I came home from driving my truck last week and was working on some instrument lights, and when I tried to start my truck again, didn't start. It will turn over and act like its catching (meaning if I continued to keep the key in the start position would cause starter to grind). I thought maybe I had let it get too low on fuel, so I put in some gas I had in the garage. No luck. Fearing I had put in some bad gas I drained the gas out, put in 4 gallons of fresh gas and took the carb off to clean. Put carb back on, put in some new plugs and same problem. If I pour gas into the carb it will allow me to crank until gas is gone, but then same thing...acts like its catching but nothing.

I'm afraid now that maybe when I was fidgeting with the control lights maybe I screwed something up electrically. The carb bowl is filling up with gas, so I don't think its a fuel problem at this point.

With this amazingly vague description, any ideas how I should chase this down?

Thanks Chad