1983 K30, rebuilt carb, still a turd that won't run

[46binder]

I need to vent, I just bought this as a winter beater since I'm not done with my 1980 Scout.  I put a junkyard Chevy TBI on the IH 345 motor, and it backfires immediately under load.  Fuel pressure is 12 PSI all day long, timing and rotor phasing has been checked multiple times, and looks great.  Idles and revs great in park, but backfires when in drive under load.  Back to the Chevy, I rebuilt the quadrajet, followed Youtube videos and internet articles.  Bought a book, but that didn't really tell how to adjust or trouble shoot, not interested in performance yet, I just want it to run.  Had multiple problems along the way since I bought it.  Replaced the tank selector valve, PO had installed a new fuel pump already.  He thought the float stuck, but 'wasn't a Chevy guy' and really didn't know anything.  Carb was rebuilt, new float, followed all directions, set float per factory.  New electric choke, new oil pressure sender, but choke light still stays on.  i have 12 V to the wire, but can't really tell if it opens fully, its been single digit weather here.  Truck starts, runs great, idles, then I shut it off.   A few hours later, it runs rough, need to really run it high idle or it dies.  Later it just won't start.  It starts again, idles great, let it warm up, go take it for a test drive, and it dies and won't stay running.  Sure seems like intermittent fuel issue.  I think I know what it is, its old gas and crap sitting in the tanks for how long.  Truck was sitting for possibly a year before, and it was never taken care of.  I know I should just pop for a new tank, the drivers side leaks anyways, and run new lines.  But, that's why I'm venting.  This wasn't supposed to be another project, and I sure don't want to deal with this in winter.

[46binder]

So I left the truck this afternoon and it wouldn't start, and when it fired, it would stumble and die right away, like not enough gas.  Just went out, and it started right up again, idled and ran great.  I'm running off the passenger side tank, which was pretty empty when I bought the truck.  I think the truck had been sitting or rarely used the last couple years, the owner was elderly and I bought it when he was in a nursing home.  I'm thinking the tanks pickup tube is full of crap.  When I switched to the tank I had about 3 gallons poured into it, and I added 5 more this afternoon.