Rob, Some additional notes: I have heard that the Sanden SD-508 is being replace with the SD-5H14. You might consider using a Sanden SD7H15 compressor. It has a slightly larger displacement than the 508, which will give you slightly more cooling at (and near) idle. SD-508 & SD5H14: 5 cyl, 8.4 cu in (138 cc) SD7H15: 7 cyl, 9.5 cu in (155 cc) John