This is for our Clark S120XSL forklift with Perkins 4.236 propane engine. These engines are known to throw down some serious oil pressure on cold startup, and have high oil flow rate in general. I wanted to give the engine the best chance of operating without bypassing, so I did some research and found a much longer version of the FL1/PH8/51515 filter in the NAPA Catalog. This is a direct cross for the Baldwin BT238 and Donaldson P551603. Both average a touch over 7" long. Pic is of it next to a Fram XG8 Ultra Synthetic from a '67 Shelby GT500. Not going to use it on the GT500, because it will probably drag on the floor.