A take-off cover bolts to the block in place of the oil filter and redirects the whole oil flow out to a remote filter housing or cooler through two female 1/2 BSPP ports. Unlike a sandwich plate, no filter remains on the engine, which is the answer when there is simply no room left in the standard position. The centre filter thread is 3/4 x 16 UNF, so verify your engine’s filter thread matches before ordering. Billet construction keeps the cover rigid against the sealing face. Get the feed and return orientation right, because reversing them will send unfiltered oil to the bearings, and use hose rated for hot engine oil on both legs of the circuit.