My 01 XJ came with a Sanden SD7H15 compressor. Most of the auto parts stores list SD709 compressors as direct fit. They look the same. Auto Zone sells a SD7H15 for about $25 more. From research online, about all I can find some people saying SD709 were originally for R-12 and seals may not be compatible with R-134a but people are saying the SD709 made today can use either. Does anyone know if this is true? I'm guessing most folks are dropping SD709 in their XJ's and there are no problems.