i have a 95 z-28 m6 and i was going to change the gears out in my 10-bolt for some 4:10 but everyone says its waste of time because it'll break and i'm better off buying a 12-bolt but i cringe everytime i look at the price of a moser 12-bolt. This local drivetrain shop owner told me once that he could builds 12-bolts starting at $900. can u save alot of money by going with a rebuilt 12-bolt rather than a brand new one?

Also what about 8.5" 10-bolts? are they any better and our 7.5"'s?

 

umm. you may have some fitment issues. whatever rear end you buy, you will want to make sure it has provisions for a torque arm. i doubt he gets a hold of many of those. but if you could find a used one for a good price, i'd get it. i'm in the same boat as you though. i have a brand new set of gears, install kit, and rear end girdle, but then i changed my mind.

chris

 

Same boat as both of you! spent about 430$ for 4:10's ,install kit, Girdle, but i really dont got 2500$ to buy a 12 bolt. im just gonna put them in my 10 bolt anyway and just dont lauch the car as much

 

I think the 8.8s are less $$ than the 12 bolts.

 

i figured the catch must be that it's not a rear-end that would easily fit in my car.I don't know i'll prolly give him a call this summer and find out if he knows what he's talking about. I bet he's just unfamilar with f-bodys.

I i'm still really considering putting some 4:10s in my 10-bolt. its cheap and even if it breaks its cheaper to fix than buying a 12-bolt. u allways hear of people breaking them but i thin kits when there doing 5000rpm launches on slicks. I think on street tires it would be fine or mabye even a larger "street" tire. I guess it comes down to how much traction do u need in a street application. So if i plan to have a car with a heads/cam package, mabye 370-400 rwhp how what kinda tire would i need to have to take advantage of it with 4:10s.? Mabye if i can get away with a larger street tire i can keep my 10-bolt

 

Make sure you order a "solid pinion spacer" Helps beef up the 4:10 gear set alot from what i hear. Thunderracing has them for 18$ it replaces the crush sleeve which is the weak spot on most gear install's. the soild pinion spacer helps reduce movement in the "pumpkin" under hard launches. im gonna go ahead and install the gears anyway!

 

10 bolts are hit or miss really, my freind had 3.73 10 bolt in his '00 SS with around 340 rwhp, and broke it at the track shifting to 2nd with 275 nitto dr's after like 1500 miles, but i ran 4.10's (weaker than 3.73's) in my 10 bolt with 350 rwhp on 315 nitto dr's and launched as hard as i could without spinning many times, never had a problem. both cars are 6 speeds...that rear had like 6k miles on it when i sold it, and lots of abuse, but never gave me any problems...like i said, there hit or miss...people break stock ones on bolt on only cars on street tires, some people can launch them with slicks and get away with it...with my new setup, i need something stronger, so i opted for the profab 9 inch, prices start at $825

http://www.profabsouth.com/GM.html

 

i snapped my axle with stock power and 245 nittos.. at a 3k launch... with stock 3.42

cory

 

A "normal" 12 bolt will be an interesting fit, you will also loose or have to do a custom ABS setup, not to mention it will not be near as strong as the $2200 ones. The TA mount will have to be a completely custom setup as well as everything else.

You can try the 4.10's, but in all honesty they are a crap shoot, I spent almost $700 trying to get 4.10's to work in my car, I ended up destroying 2 gearsets, and the last time everything grenaded I took the diff out as well. This on about 300-325 rwhp and Nittos at the track and on the street.

Thus I just coughed up the $$ and found a GP on the Strange units; now, I'm just fine for a bunch more upgrades. I could have saved myself a LOT of headaches and an entire season out of commision due to screwing around with upgrading the 10-bolt, not to mention the $700 I could've spent on the 12-bolt instead of pissing it away in parts that broke.

 

wow wait 9inch for $825? is that just the rearend and not axles, diff and gears etc or the whole built thing ready to bolt in?

 

thats just the housing, but third members for 9inch's are cheap, im gonna run a stock truck third, with factory 3.50 gears and a mini spool...that will be less than $200 ...shafts are another story, but your gonna spend money on good shafts no matter what axle you buy

 

wait whats third members? So how much will it be for everything else other than the housing?

 

third member is the center section (part that holds the carrier and pinion gear) on a ford 9inch, remember, a 9 inch has no rear cover, the front of the axle comes off revealing the gearset/carrier, this housing is called the third member...as far as the other costs, i really dont know, i have not bought axles yet, or bearings

call up pro fab, theyll let you know

 

but the diff costs 200? really interesting. if axles and bearings + drivetrain shops cost to assemble and set up the gears u want in it costs less thans 1400 it would be less than a 12-bolt.

 

well see, thats the beauty of a 9 inch, with the removable third member, you can find a third member with the gears you like, and just install it in your axle, no setting up of gears...heres a pic of a third member from a 9 inch...
http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW