One last repair to complete my 63 Ford 4000, got a new flip type gas tank valve and will put it on this weekend, since it is the flip/plunger type of valve I am thinking about just leaving it open all the time and put me a brass ball valve close to the glass bowl at carburetor, this is what I did with my 601 Ford which has the screw type gas valve and leaving it open all the time with a ball valve to cut fuel off has worked great with no leaks underneath the tank. My question though is the flip type valve okay to leave open like this all the time to prevent premature leaking of this valve, also has anyone ever rebuilt one of those valves.