You need to cut the center from a newer air cleaner and weld it into the base of your original. I got a spare original base so as not to hack up mine. Alternately, get an aftermarket air cleaner. You can use an aftermarket base under the stock upper lid, as the lit simply seals on the filter. This will leave an opening around the base of the lid, which lets in more air like an open element air cleaner, but will look stock from the outside.