No need for a return style regulator. Just plumb a return line T'd off of the fuel line near the carb with a .060 or so restrictor in it like Trailbeast recommended. Connect that to your stock 5/16 line. Then run a new 3/8 line for the supply side. That's about as cheap as you can get to add a 3/8 supply and have a return to circulate hot gas. You already have a working regulator. Why buy another one.
