I like the idea of the 54 sending unit also. So I would use hard lines inside cab right? What about capping off the gravity feed? What's the proper way? Should I seal the tank after cleaning? Minor surface rust inside and out, patches really and looks like old deposits in tank.
Do yourself a huge favor. Buy a new tank and don't look back. It will give you the piece of mind of not having to deal with 60 years of deposits on the sides of the tank being dissolved by volatile additives in today's gas, and finding its way into the fuel pump and carburetor. It will be that mysterious yellow cake uranium looking stuff.
Or you can keep your old tank and have to wonder if it is causing your driveability problems later down the road.
