Hey guys!!!! Been doing jome junkyard crawling and was wondering how to tell the 9 bolt from the 10 bolt at a glance?? I know it refers to the bolts on the ring gear but the old 10 and 12 bolts had the same number of bolts in the cover. Do 9 bolts have 9 bolts on the cover as well??? Or is there some otherway to tell with out taking the cover off? Also I know of a rear end out of an 85 firebird with a 2.8 and auto that I could come and get, what would that have for gears??? I know its just a guess but what would it most likely have?? Would I have better luck finding deep gears in a v6 car or in a v8 car with auto or manual??? Just want to speed my junkyard searching!!!Thanks!!!

 

It's the number of bolts on the rear cover, not the ring gear.

A very quick glance of the cover can also tell.

A smooth cover is a 10 bolt
A cover with a rubber fill plug is a 9 bolt
A cover with a metal plug in it is a rare Dana 44.

GM produce 3 different 10 bolts over the years. 8.2, 8.5 and the 7.5/7.625. All 3 have 10 bolts on the rear cover but the rear cover is different shaped on each and none share anything similar.

An 85 Firebird with a 2.8 will have 3.42 gears.

 

9 bolt also has a lil "hump" in the middle of the cover where the ring goes