My MD has an aftermarket hydraulic system on it. It had the original live pump on it but nothing else, so I put a five gallon resevoir on the back with a screen to the pump input and a regular Grainger spin-on filter in the return line, in order to run my loader. It works great, but it"s been a few years and I would like to change the oil and the filter. I would like to put a regular IH filter on the filter head, both for parts availability and keeping it consistent. A few years ago I saw a tractor with an added-on filter like that with an I-H filter element and I copied down the part number, but have since lost it. Can any of you parts gurus give me the I-H part number for a common standard spin-on hydraulic return filter? Thanks.