External oil filter adapter, sump spacer, windage tray, for pre-1998 big twins, locates the oil filter at the front of engine, requires removal of several lower fins on the bottom of the timing cover for oil filter clearance. This fin removal is best carried out by a machinist, however you may remove them with hand tools. This unit is designed to be used with engines having factory sump spacers such as LeMans III, California II, California III, California 1100, and early California EV. When used on those models, this piece replaces the factory sump spacer. If used on an earlier model, such as T3 or 850 LeMans that do not have the factory sump spacer you will need the longer oil pan bolt kit.