Hildebrandt Oil Filter: authentically reproduced externally but modified internally to accept a spin-on oil filter. The adaption of the spin-on filter gives you full pressure filtration, unlike a Beehive filter. The filter is a very common one, used in most Ford six and V-8 engines (Napa 21515, Delco PF2, Fram PH8). It is shipped with a NAPA filter that has a Nitrile anti drain back flapper in it. The inlet and outlet holes are drilled and tapped for 3/8 pipe thread. There are four drilled and tapped mounting bosses on the rear as on the originals (~1 3/8" high by 3" wide bolt pattern. It is also shipped with four 1" long 1/4-20 studs for mounting purposes.