I'd be curious if your carb was running dry too. I know you said you rebuilt the carb, but it you blow into the gas line going to the carb and your ears POP and then check to find the bowl empty... A sticking float is your culprit. Happened to me at least once... ha.
Hope the issue turns out to be a minor fix for you.
Good luck.
Jerry Wilson

1959 Chevy Apache 3200 Stepside
In the Stovebolt Gallery
Restoration Journal on Facebook

"A government that robs Peter to pay Paul can always depend on the support of Paul." ~ George Bernard Shaw