MightyMouse61

OK, wanted to go straight to the olds guys on this one.
I have an O type 10 bolt(always wondered if when ppl say 0 type 12 bolt, they mean 10 bolt) out of a 69 cutlass. It will need a rebuild and has an open 2.78 gearing.
my questions are, how strong are these rear ends and is it more economical/reliable to go with a GM corp. 12 bolt rear end or build this one?

The rear would be going into a 70 chevelle, mostly drag strip use, occasional street use.

507OLDS

Since you are putting it into a Chevelle,and you are doing a lot of strip use,I would opt for the 71-72 8.5" 10-bolt,from a 71-72 Cutlass/442 or 71-72 Skylark/GS,or go for the 12-bolt Chevy rear. The O-axle is a good rear,but parts are scarce,and therefore expensive.By the time you have the O-axle done,you will be real close to having a 12-bolt chevy rear.The Chevy rear parts are plentiful,and less expensive than the O-axle,but the housings are valuable.Getting one of those at a good price is the key.
The 71-72 8.5" 10-bolt is the least expensive option,and is just as strong as a 12-bolt Chevy.

MightyMouse61

thanks

Aceshigh

I agree ^ ^

Yes it is.

I just pulled my 70 Olds O faux 12 bolt out because gears + carrier = ~$975 before install.

I bought this Chevy 12 Bolt off a guys 71 Chevelle on Lateral-G.net for $1000
with all new rear disc brakes, Eaton posi, 3.73 Richmonds, and 30 spline Strange axles.
It's even got the Moser 12 bolt T/A cover too. Granted, I got lucky in finding this option,
but I have a hell of alot stronger rear end, and if I ever change gears, it will be cheaper.

You'll find a TON of stronger 12 bolts from Chevy out there, just be patient and you'll snag one cheap.
Browse www.pro-touring.com and www.lateral-g.net and www.yellowbullet.com
Those guys all have serious money into their cars. Pro-touring or Drag.

There's also Tom who buys cores and rebuilds them whose on various sites I'm on. http://12bolt.com/
He also does "How To" video's on YouTube > > http://www.youtube.com/watch?v=UPXf1OR9Lnk
Olds12BoltDiscBrakes3.jpgOlds12BoltDiscBrakes7.jpg

507OLDS

AcesHigh,
You were fortunate to find a rear,with all the work done,and get a great deal on it.He may or may not get as lucky.

Lalo442

I was looking at the Eaton catalogue and was wondering if the 19674-10 would fit in my 69 is it the same type? And when they say 10 bolt they are refering to the bolts on the ring gear because mine has 12 bolts on the cover ....?

monzaz

WHEN WE SPEAK of 10 and 12 bolt MOST people refer to the cover which is misleading as the cover will sometimes macth the ring gear bolts .

The ring gear bolts are what MAKE the 12 bolt a 12 bolt and a 10 bolt a 10 bolt. More bolts we have holding the ring gear stable the better. Pinion shaft size is another factor for strength that needs to always be considered as it will take the torque load into the ring gear with less deflection.

If you have 12 bolt cover and 10 bolt ring gear the 19674-10 unit will NOT FIT or work in any way shape or form.

That is for the early Olds 10 bolt covered rears (Pontiac 10 bolt 8.2 you might as well call it.) all 10 bolt BOP rears shared the posi units and gears up till 1967. 1968 buick olds went out and invented there own rears in search of the 10 bolt 8.5....

I am trying to supply 12 bolt olds parts at a MUCH BETTER price then others have done. I sell reconditioned retro posi units and NEW posi unit and even full spools for DRAG RACING your nostalgic 12 bolt olds 'O' type rear.

Do not give up on your original Olds rear...I am trying hard to supply parts to keep it on the road and strong running.

True trac and eaton posi unit can be special ordered too.

Jim
330 659 7117

Lalo442

Great I won't give up on my Olds rear end especially because I mostly just cruise with an occasional Burst to clean out the carb will definitely look here when I am ready to upgrade from my Peg Leg maybe with my next Tax refund 2012.....:-)