The Promax is a 51241 BLP metering block with Promax laser engraving on it. My suggestion is order a 51251 metering block from BLP, it has the idle feed lowered. You will need plugs for the mainwells, mixture screws and seals, and gaskets from BLP. To finish you will need a box of 6-32 x 3/16 and a box of 6-32 x 1/8 brass set screws from McMaster-Carr to make your own emulsion bleeds and blanks (3/16), and for idle feed restrictors (1/8). A 61-80 drill index set, a pin vice, and a slow speed drill will get you drilling your own restrictions. All of this and still probably less than $150.