1967 econoline pickup issues need help with

Hello everyone
Just purchased a 1967 econoline pickup to restore. 170CI 3 on the column.
Barn stored for decades. Did not take much to get it running and driving and it is currently on the road. The first problem I would like advice about is with fuel delivery.

When I got the truck I filled the tank with gas and noticed that the gauge said 3/4 full.
The second more distressing problem was after driving it about 80 or so miles, I was driving home from work and it died going up a hill. I had to add a gallon of gas to the tank and it started up!!! When I got to the gas station I thought I would be adding more gas but the tank was still full.
What am I looking at here? The hose in the tank not sitting right? Tank not venting?

The second thing is play in the steering. Has anyone adjusted their steering box and how much of a screw turn am I looking at to get mine tight?

Thanks for the help!

I would say to drop the tank, see what condition the insides are in, see that the fuel pump hose is actually connected to the pick up tube and not mixed up with a vent or vapor canister hose,,,,,see that the pick up tube goes all the way down to the bottom of the tank,,,see that there is a filter on the end of the pick up tube,,,,,after all these years, you dont know what has been changed or modified so start at the beginning, make sure all is good then see what else needs to be done.....

It's possible the pickup tube in the tank is rusted through near the full level of the tank. If so, it will suck air once the fuel falls below the upper edge of the hole.