You can loosen one of your temperature sending units. They're on the 2F head, next to the carburetor. Should have a single wire hooked up. Loosen the sending unit, enough to allow the air to escape. A little bit of coolant might bubble out, and thats ok. I've burped my 2F a few times this way.
Tow bar. No need to remove the drive shaft. Just put both transmission and t-case in Neutral. Get yourself some magnetic trailer lights and you should be good to go.
I've towed mine this way many times behind a first gen tundra and a 2000 F-150.
It's not so much the towing vehicles ability to...
I would check that everything related to the starter and ignition is grounded properly. Including that little condenser.
I had a similar issue, but I honestly can't remember what the cause was and how I fixed it. I did install a @Coolerman fusible link, which negated the the auto zone inline...
Pulled it into the shop here at work. Treated some of the rust. Had this can sitting on the shelf and figured it couldn't hurt.
Waiting on some polish and wax. Going to detail this thing before winter. Also want to try the Fluid Film on the undercarriage.
Mines a '76. I removed the brake handle bolts, so it just hung there, but otherwise I did the adjustment while the cable was in place. Tedious, but I got it done.
Maybe spent 45 minutes to get it working.