I have a return "port" on my tank. Not sure the correct term of this port but basically have two ports on my tank. One is used for to feed the carb and the other (return) I have capped off at the tank. Been thinking installing a return line to the fuel system. Your method sounds pretty interesting. Like to have more info on the restrictor you used. Right now I have 7 psi at the carb without a pressure regulator using mechanical pump. Had one of those Carter mechanical fuel pumps on there but it was junk. It never had good fuel pressure. Went with a standard pump and it works like a charm.
