[hobgoblin351]

It's the number of "barrels" or venturi. Named after the guy who invented them, G.P. Venturi. I had the Holley book handy so I looked it up! lol You should get one of those repair books at the auto store. Chilton makes some but there are others. It'll guide you through basic maintence and stuff. Changing plugs and filters is simple stuff. But adjusting the carb is tricky. So read the book and folow it's instructions. I wish I could say I know alot about inline 6's and 1 barrel carbs but I dont. lol Oh, I dont know how green you are as far as working on cars, but when working on the carb Dont drop anything in! stuff a rag in there to make sure. Good Luck