I'm about to convert to r134a, and was looking at receiver driers. Seems some places list two items for the V8, for example: http://tinyurl.com/3x9e2w - I can't see any difference but the part number. http://tinyurl.com/3xetkq - not sure I understand the differences - they look different, but I don't know why. Thanks for any help/suggestions. Arryn