I just got a 91 RS, and I am planning on swapping the motor out. I have the stock 10-bolt GM rear end, and I was wondering how much HP they can really handle. It doesn't have posi, so I was thinking of putting in an Auburn posi unit. Is it worth the money? Would it be strong enough to handle 350-400 HP?

 

Your best bet is the SLP take-off torsen posi unit for $99 (http://www.slponline.com/) and a set of used gears from a 4th gen car (3.23 or 3.42). Dont forget to change the speedo gears in the trans, too. People have run 12's in the stock 10-bolt so you should be ok. Other people have stock engines that have broken 10-bolts. Its all a toss-up.

 

I don't know from experience, but I read a post that said the 10 bolt is only good up to about 400 horse.

 

Also forgot The SLP take offs are on sale for $84.99 ( I think that's right)

 

If your planning on 350 / 400 HP, forget the take outs. That's why they got them, they won't handle the HP. Your looking to spend about 1000.00 to make a good 10 bolt. Ask me how I know. You can get a brand new eaton on ebay for less than 400, I did. 28 Spline axles 230.00, bearing kit 80.00, girdle 140.00. And you can get gears used or new 170.00. Then you have to have um set up or do it yourself. I got my eaton, brand new 319.00. Ebay.