$522 isn't 'astronomical', particularly if you buy a few incorrect items instead
.... "port holes" doesn't tell the story, there may be inlet and outlet for water cooling [each side of the head], lube inlet and outlet [in the 'crankcase'], and one place for air outlet, with a smaller nearby aux port for the unloader function ... you need to identify what the ebay compressor actually is, rather than just what it's from, you might find it's made by Bendix, the most common ... you might be able to ID it using the pics
in this catalogBill
