I was looking at Boxerworks on-line store, and I saw two oil filters that are hinged, one was for oil cooler equipped bikes only and the part number ended in the digits -575, then another one listed as hinged filter for 1970-1995 bikes with a part number ending in -570. So I guess if you don't have an oil cooler equipped bike, you need to make sure that you get the correct hinged filter. I wonder what the difference is? I know I had to change the center pipe in the oil filter cavity, when I installed the oil cooler kit, I think it was remove the short pipe and install the longer one.