99power

no need to change rear ends. a good posi and gear should be good to around 700hp easy. as we used to have a 87 grand national with 1000hp no problems with rear end now remember there's a big difference in weigth.

O3GMC

How strong are factory gears? Can they hold up with an eaton posi?

Mr. Sandog

Here's an interesting post:

G80

zippy

it is interesting, but i've seen stock truck's do that to a gov-lock. on the other hand i've seen my buddies s10 with a stock 8.5 in it (still has the stock gov-lock) pull a 1.51 60' time. his truck has made more than a few pass's in the 10's. weight is a big factor in the 10 bolt's strength. you can also add braces to them to keep the twisting effect down.

chris99gmc

I hope so... I really think my rear is gunna go next, if anything .. i still haven't put an eaton in yet... i think I am more or less waiting for it to go first.

12sec.5.3

iTrader: (1)

Or Eaton

BADMOFO

I had an Auburn Pro Posi in my Olds and it was sweet, but I understand that the Eaton may be the better way to go for our trucks as they are re-buildable and the Auburns for the 10bolt are not. I might be wrong...but that is what someone else was saying. If that's the case, I'd go with the Eaton also for the "just in case" rebuildability of it...lol. (if that is even a word!)

Last Call

iTrader: (4)

I wouldn't wait for the carrier to go. It is a lot more costy because I'm going through it right now. A posi and install is around $500. A falied carrier, new gears, bearings, and seals will cost and anywhere from 600-800 plus more labor to do it. Do it the smart way if you can because when a carrier goes it ***** up everything else.

James B.

iTrader: (1)

I love that post

That happened a long time ago. I did quite a bit of homework on the 10-bolt and concluded that it wasn't worth spending a penny on. It's easy for us OBS guys to swap in whatever we want to, you NBS folks have fewer choices unfortunately.

I'm a big fan of the 10.5" rear. The pinion shaft is supported by bearings on BOTH sides of the pinion gear. The carrier will have three or four spider gears depending on which differential it is. (open has 4, posi, locking, etc mostly have 3) There is a good choice of gear ratios available for it. Eaton makes two different true Posis for it - 4.10 and lower, 4.56 and higher. There are no c-clips, not even in one converted to semi-float like what I have. On the conversion I have, made by Drivetrain Direct in Corona, CA - the stock brakes bolted up. Sure it's heavy, and I mean TWICE the weight of a 10-bolt, but I never even think about it anymore, it just works.

Scream

iTrader: (6)

Since we don't have many options as far as factory GM pieces, wouldn't it be best to look into an aftermarket 9" or 12-bolt? Not that many on here really need a super beefy rear end, just throwin' it out there.