I have been looking for an F4B intake (e-bay etc) and have found one for a decent price and the water jackets are really sound, no stripped pipe threads etc. The question I have is that everyone that I have seen has two oval slots under the carb (one slot for primary and secondary on left side and one slot for primary and secondary for the right side) The one that I can get has 4 holes other than 2 slots. These are actual cast holes and not the gasket. I believe it is original as the casting states F4B. has anyone seen this and what are pros and cons of this verses the 2 slots? Brian