Oil Pump Body

Oil pump body is drilled and tapped for a 1/4" x 20 thread.
The Harley Davidon oil pump, 678-41A, was originally used for 1946-1947 Knucklehead Big Twin engines and early Panhead models (1948-1950). It was later replaced by updated part numbers in the 1950s, such as 26201-48 for Panheads (1948-1952). Although no modern chart exists, compatibility and oil characteristics are well documented by classic motorcycle enthusiasts and suppliers.