Are you talking about this company:
www.customrebuiltcarbs.com
Custom Rebuilt Carburetors buys, sells, and rebuilds all kinds of carburetors

I have had excellent results from ProSystems Carbs, as have two of my friends. Beautiful response, right out of the box and not a lot more than an off the shelf HP Holley.Anyone have experience with a custom carburetor? How much did you notice in performance? Good company to use? Why is it considered custom? I know it’s built around your specific set up, but what do they do that someone who can tune are carb can’t?
Trying to decide on a custom carb or going Holley EFI on a 93 pump gas 383 build.
Same with me. I sent Patrick all my engine information and he built me a carb that worked perfect right out of the box.I have had excellent results from ProSystems Carbs, as have two of my friends. Beautiful response, right out of the box and not a lot more than an off the shelf HP Holley.