Not all Carburetors Coat the same! Now this really sucks when your customer sends you his all original 66 G.T.O Tripower. Of course, that is the way they came from Pontiac. I have at least one hundred N.O.S. or Rochester Remanufactured Examples, tons of individual castings and no two are alike. I prefer to mix and match to get them close, but when it's their Real Deal Tripower, you should not!
