Ok I found a borg warner 9 bolt for sale for $300 with disc brakes. I know there better then the 10 bolts by alot, do the 9 bolt`s have C clips??? and what gears do they have?? I popped the diff cover and it looks good inside. how do I tell the gears, will the ratio be stamped on the ring gear??? it still has the tags but there so rusted I don`t know if I can read them. are they hard to rebuild?? and how much do you think it would cost to rebuild it. If I get this rear end I plan on putting it behind my 383 with atleast 400hp + I`m going back to look at it again on friday so what ever you can tell me about the 9 bolt would be VERY helpfull. Oh and is the posi rebuildible?. The guy I`m buying it off of has NO CLUE what this rear end is, He thinks it a 10 bolt, but I know it`s a 9 bolt I knew as soon as I saw it. it has the rubber plug in the diff cover and I counted the bolt just to make sure and theres 9 . I`m going to try to get him down to 200-$250 since he said he just wants it gone

 

10 bolt > 9 bolt

 

There should be some numbers stamped on the ring gear. My 9-Bolt I bought for my Firebird had 37/10 stamped on the ring gear for 3.70 gears.

 

my buddies had 3:27's in it if i remember correctly. it was out of an 87 iroc with an L98

 

The most common BW 9-bolt ratios are 2:77, 3:27 & 3:45 for TPI cars. The best year for a 9-bolty would be 1989 for the PBR brakes. The ratio will be stamped on the ring gear. Most of the ratios I mentioned will be limited slip and have 28 spline axle shafts. Other ratios that came on early Carb cars are a whole different matter and could have anyyhing. I would stay away from them. As a point of info, Parts are rare, hard to find and expensive. Check for info on www.thirdgen.org for additional info. I have a 89 BW that I swapped on to my 87 IROC and I am glad I did, it was a good upgrade (the best part was the 11.655 rotors & aluminum calipers with a working parking brake).

 

I saw 9 bolt ring and pinion gears going for around $300 on ebay