Twenty years ago I was using a 4500 series Dominator carb on a BBC. I had added a set of anti-reversion stacks to the carb, at least I think that was what they were called. They consisted of (4) short chrome stacks with a "X" type retainer that clamped all of them in place using the carb air cleaner mounting stud hole. They were a push-in fit at the top of the carb venturi and sometimes were a pain to get in there straight! I always liked the way they looked more than I was looking for any power gain. I want to put one of your new "Ultra Dominator" carbs on my BBC Pro Street Corvette, but not if these chrome "stacks" are no longer available. I can't seem to find a part number for them, are they still available?