Sorry this is being brought up again.
I was under the impression you must run an oiler with this compressor in an air set up; but I saw somewhere that the 708 has an actual sump built in, similar to the Yorks. Can anyone confirm this? If so I am going to use my factory compressor rather than my York 210.
the 508 has an internal sump, and you only have to change one brass internal oiling tube orientation to use it for air. There is a company that sells modified 508's for EDC, I think maddawg on SSM has one and he posted the web address for them once.
The 708 is a combined system, you will need an oiler. The 508 was only found rarely on early Mazdas, My nephew had an 86 Automatic with a Sanden 508, but my 87 automatic had a 708.