Best Carter 4 Barrel Carburetor for a stock 273?

I have an old competition series carter on a 400 in my rat rod. It works better than any edlebrock ive ever had. I think they messed something up when they put that shiny coating on them. Stay away from the 750 eddys, Ive had a few of those new and used... every one had an off idle lean spot that wont go away no matter what ive tried.