No, it won't work because if you think about it, the header tank is really just acting like a large volume extra bit of fuel line. The only way to make it work is to use a fuel pump to pump fuel from the main tank (Uniflow won't be needed then) up to a normally vented header tank where the vent line allows overflow (recirculation) back into the main tank. This overflow line should be large enough that the pump can't build up unwanted pressure in the header tank. Muffler pressure into the main tank will still be felt in the header tank.