GM 12 Bolt Rear End to G-Body

[fleming442]

And more expensive to build as well

BUT, your axle won't go flying out when the c-clip fails!

 

[500/600]

My ‘70 Skylark had a ‘71-72 Cutlass corporate 8.5” that had non c-clip axles. Nice setup.

 

[gnvair]

If you are concerned about axle retention you should reflange the housing with Moser 9" style ends.

 

[fleming442]

If you are concerned about axle retention you should reflange the housing with Moser 9" style ends.

Back when I did the 67 about 12 years ago, nbuilding a 12 bolt was about $1900 with Frod ends. I got a Moser 9 delivered to the door with all the same stuff for $2000.

 

[gnvair]

Back when I did the 67 about 12 years ago, nbuilding a 12 bolt was about $1900 with Frod ends. I got a Moser 9 delivered to the door with all the same stuff for $2000.

I was talking about adding them to an existing rear. I'd still rather have the Chevrolet 12 bolt. Let the Oldsmobile guys swoon over the Oldsmobile 12 bolt. I think you made the right choice for your car.

 

[olds307 and 403]

It isn't an Olds 12 bolt cover with 10 bolt ring gear 8.5" which still way stronger than a 7.5" rear, good for 500+ ft/lbs. They are usually 28 spline bolt in axles but have only 3.42 and 3.90 gears available new. The 70 with the oiled axle bearings is the best, which I have. The 71 through 76? with the "Coporate" 10 bolt 8.5" with bolt in axles is the ultimate 8.5" to build. Canadian cars in 68 and 69 got the Chevy 12 bolt axle, which is what he is looking at. The big weak spot is the stock necked down axles. Once replaced it can take some serious abuse.

 

[TURNA]

the bolts refer to the ring gear not the cover bolts even though they sometimes match

 

[pontiacgp]

Chevy had some Ford style rear ends from 58 to 64 in some Chevy's and in the Corvette....they dropped to ball when they shut that program down. You can build the 12 bolt to take as much power as the 9" but you'll spend lots of $$$$ doing it.

 

[TURNA]

I say it everytime this topic comes up...

Even Chevy knows when they are beat......

Which is why the New COPO Camaro has a Ford 9 inch in it

 

[abrodeur79]

Have you checked into aftermarket 12 bolt that fit a G body. And or an 8.5 out of GN

I have looked into it. Pricing for those is a lot especially with exchange, duty, shipping to Canada. And Grand National or any other G that ram the 8.5 from factory are not easy to come by up here either! I wish I could go with one of the made to fit rear ends!