Trying to install a JD ported filter cover (PN T31170 Or L55982) on a JD 4020/JD4010 as a replacement of the factor non-ported cover. The ported filter cover will fit, but it is longer than the non-ported cover. I know that this has been done using a JD factory issued holding bolt, but I just do not know which bolt. Anyone out there done this? If so what bolt did you use and what is the JD part number? All of the non-ported cover parts will work except the bolt. Since the ported cover is longer it will require a different bolt which would provide for a different holding snap ring location. It appears that you use the same hydraulic filter with the ported cover as was used by the non-ported cover but one option would be to use a longer filter if that would work. Anyone out there done this? Can anyone be of any help? Thank you.