The OP didn't say it was a '54 tank. That was Kevin's guess.
If it is a '54 tank, how is the engine getting fuel?
I think it's a '52 tank with a '54 sender stuck in it and the fuel line from that sender is capped off.
But, I think we need a lot more information.
1. How are the two tanks connected?
2. Does the in-cab tank have an outlet below the cab floor?
3. If so, is that where the two tanks are connected?
4. Sending unit doesn't need electricity for the engine to get fuel. That's for the fuel gauge.
5. Are you using the stock mechanical pump?
6. Was this truck running before you bought it? Aside from the ether, did you ever see it run on gasoline?
7. Pictures of the engine bay, carburetor, fuel pump, fuel line connections at the tank(s), etc. will help a lot.
Last edited by Otto Skorzeny; 02/20/2023 9:57 PM.