If you can't find a dependable check valve, I've used several of them and in about 6 months the fuel freezes them and no amount of pump pressure will push them open (personallyI think the gaskets/seals swell up and block fuel flow) The best solution for me was to use a small fuel pump with a 1973 Chevy fuel tank change over valve (3 places to hook up, one in two out. Just find out which ports are open when no power is hooked up and block the outlet off and use the other. Fire the valve with the same wire that runs the pump. These valves are available at most auto parts places. I'v bought them at advanced auto and O'Reilly. When I asked for a fuel change over valve, I got the deer in the headlight look, and was told they didn't have any thing like that. Told them for a '73 Chevy C10 and they took it off the shelf