need info on this carb

As your facing the front of your car/engine the vertical surface of the left front mounting boss is where to look for the part numbers the others are talking about. I agree with rumblefish that this is an aftermarket remake of a Carter AFB manufactured by Weber. These were also sold under the Edelbrock name for a time. I can't tell if its a competition series like rumblefish but seems likely as air horn seems to have a cleaner area where the Carter competition series carbs typically had an aluminum nameplate.