I've had '50 3100 for over 10 years, and, in that time, have never been in such a quandary.
I converted to 12 volt several years ago, put in Old Air a/c, and pertronix pointless ignition.
A few weeks ago, the A/C compressor wouldn't come on, and I got that worked out, then recharged the system. Then when I was running the truck with the a/c compressor on, engine started sputtering, then died. I got it started, but just barely. The carb was super flooded; took off, blew out passages, to no avail. Even put in another carb that works (still nothing). Haven't been able to get it started since.
I've replaced PErtronix with regular points, switched out coil, checked compression and spark (i'm getting spark), put in new condenser, and put in new high wires from coil and to spark plugs about a year ago...practically brand new. I've found TDC, replaced rotor in number 1 spark plug position, gapped plugs and points to spec. I'm getting gas to carb, spark to points...have NO idea what it'd could be. I suspect there's a short some where, but have checked everywhere. Wow, I'm lost. Any help??