Just picked up a disc brake 9 bolt at the junkyard Sunday. Got the whole thing (rotors, calipers and new looking pads) for $81. Got it home and removed the cover to take a look (never saw one before, all mine have GM 10 bolts) and count gear teeth. This thing has 12 teeth on the pinion gear and 37 teeth on the ring gear - that makes it a 3.08. The tech. sheet in this web page doesn't list any 3.08 geared 9 bolts for any year. Is this a strange ratio for a 9 bolt or is the tech. sheet short on data? The rear end was under a 1985 Trans Am (fuel lines on the passenger side frame so I assume it was a carb. 305) so it couldn't be the original rear (according to the tech. info). If it needs bearings, positraction parts, etc. can I order them from the Chevy store downtown or is it an internet search type of thing? Thanks. Love those junkyards!!