Try this site. You can look up parts for your Montana, the only problem the Montana part numbers are no longer any good from what I have found. I look up my parts in the LS tractor listing because I know the comprabable model, My tractor is a Montana R4944 which is the same as an LS 4020. When I take the part numbers back the the Montana site and look up the LS part number it corrisponds the the oly Montana part number and the LS number, I guess you would have to do it to make it make any sense. The easy way is to look up your part number and call Sundowner and have them cross reference it.