http://www.promaxcarbs.com/
I sent them my 440 6bbl setup that was running good, but I wanted to get their throttle plate w/angled idle mixture screws for the rear carb, their jetable metering plates for the outboard carbs, and their advanced metering block for the center carb. I also had a stripped screw hole in the accelerator pump housing on the center carb that was holding, but it needed to be repaired for peace of mind. I also got the lower and upper stainless steel braided fuel lines w/inline reusable fuel filter and pressure gauge.
WARNING if you get the braided fuel lines FLUSH them out before you install them!
Also tech support is hit and miss, but good when you get in touch with them.
I also got 3 temporary clear plastic fuel bowl plugs to adjust the floats.