Went to Daytona Parts CO yesterday and spoke with the owner. I wasn't able to take any notes but if I got everything correctly the universal carb he sells is manufacturer in Argentina by a CO that's been in business for many years making carbs for Chevy & fords . Anyway their universal carb is a redesigned Holly carb with improved features to correct any short commings from the original. They are brand new and actively manufactured. The Chevy replacement carb is basically a copy of the zenith 28. The Chevy replacement carb is is currently under a design change to add a high speed adjustable jet as on the universal carb. The owner is very knowledgeable and very helpfull. Either one or these carbs maybe the way to go. Currently he is recommending the universal carb for dual carb applications. He spent a good 45 minutes with me explaining his carbs and his operation.
