russ d
+1y
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.