Sputtering under load - quick help pls

[phlegm]

Good Morning guys,

Had to cancel my appt for tires and alignment this morning. Yesterday I went to go for a drive and pickup a new headlight, getting excited that we were registered and legal and ready to go (my first mistake). SO heres the story tell me what you guys think.

1. Truck sat with VERY little gas in it for years
2. Got spark and put 5 gal of fresh gas in, got it to crank.
3. Fuel gage stuck on empty
4. Got suspension work and carb rebuild done, took it for a drive
5. It stammers and sputters a bit at first, while driving a half mile or so. Stopped, checked my bad tire, got back in ran a lot better.
6. Got up to 50 MPH after that at one point drove about 3 miles to a friends house and back, no problems.
7. Got in truck yesterday, cranked fine rolled out of neighborhood fine (low speed).
8. Got out of neighborhood, it sputterd some but still got up to 40ish....
9. Got on highway, sputtering got progressively worse and it would not allow me to gas it at all without almost stalling.
10 get to parking lot, I can rev it in neutral with little to no sputter.
11. Almost didnt get out of lot on highway... .got to 35 MPH but it was struggling and I had to do it very very gradually.

Here are my thoughts, since it ran so well the other day I think the carb rebuild is a good one. Since the gas gauge doesn't work and it sat with very little gas in it I wonder if the fuel sock in the tank got crusty and is bad. I want to check it this weekend but dont own a tank ring tool, and cant find a locally sourced fuel sock.

Here are the questions
am I on the right track?
how do I get the sender out?
What am I looking for in a "good Fuel Sock"?
If it is fuel related, how do I know if the tank is corroded?


Thanks in advance,