hesitation/cutting out

Probably a stuck float, your carb need rebuilt. That's why it runs great at first until you open her up and need more gas, the bowl runs low on gas and float is sticking to keep it from fillin up. That's IMO, if all the other items you checked were fine, did you try o empty anything out of the fuel filter you changed?

I just cleaned out the gas tank of my '70 Mustang, removed the rust exposed bare metal and used POR-15's coatings to refinish the inside of the tank. If you ever need to recoat the inside of a steel gas tank check em out, about $60 versus $200 or more for a new tank, then all the mounting hardware and fittings and sending units you could be over 300 easy. (http://www.por15store.com/POR-15-Tank-Sealer-Instructions.html) Those old tanks will get so much rust filters, lines and carb will clog quickly, especially if you don't always park it with a full tank of gas.