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Hi I need help identifying my rear end. It is in a 1972 olds cutlass supreme convertible, Rocket 350 with TH-350, need to know which axle typ it is because want to install posi in it and which I should order
That's the Oldsmobile version of the Corporate 8.5" ten bolt used under every Cutlass Olds built in 1971-72. Bolt-in axle shafts, so the bearings and seals are different, but otherwise identical to the Chevy 8.5" 10-bolt. "SA" is the 2.73:1 open axle.
That's the Oldsmobile version of the Corporate 8.5" ten bolt used under every Cutlass Olds built in 1971-72. Bolt-in axle shafts, so the bearings and seals are different, but otherwise identical to the Chevy 8.5" 10-bolt. "SA" is the 2.73:1 open axle.
Ji Joe I
ask because of the housing here it looks different to other 8.5 axle GM and how many spline has it stock
thx for your help
Don't worry about those "horns". Look at the side of the center section for two parallel ribs, the front sides of the center section for a cast in block "O" that is the identifier for an Olds version of the corporate 10 bolt rearend, and the top of the center section for a drilled boss where the brake junction block bolts on. I think the Buick version (that sometimes was used in the Cutlass line) has an A instead of an O, but is essentially the same.
Oh yeah, and that 407296 casting number is a dead giveaway.
Don't worry about those "horns". Look at the side of the center section for two parallel ribs, the front sides of the center section for a cast in block "O" that is the identifier for an Olds version of the corporate 10 bolt rearend, and the top of the center section for a drilled boss where the brake junction block bolts on. I think the Buick version (that sometimes was used in the Cutlass line) has an A instead of an O, but is essentially the same.
Oh yeah, and that 407296 casting number is a dead giveaway.
Can anyone tell me what rearend this is? I know it’s a Oldsmobile but I don’t know what spline or anything. I want to change my gears. Thanks.
You have a ten-bolt, 8.5" ring gear "corporate" rear axle, as seen in all 1971-72 Cutlii. Other than the bolt-in axle shafts (as opposed to C-clips), the internal parts all interchange with those for a common ten bolt Chebby axle. Parts pretty much grow on trees. Yes, you can run the normal Chevy internals without the C-clips.
You have a ten-bolt, 8.5" ring gear "corporate" rear axle, as seen in all 1971-72 Cutlii. Other than the bolt-in axle shafts (as opposed to C-clips), the internal parts all interchange with those for a common ten bolt Chebby axle. Parts pretty much grow on trees. Yes, you can run the normal Chevy internals without the C-clips.
1971 -1972 Chevy A body ARE 8.2 not 8.5 so you should specify that the (camaro are 8.5) 1973 -1988 chevy a x b c body Truck 1973-4 ish -1987 with 10 bolt round cover like the 8.5 are inter-changeable. Just trying to keep things clear for everyone.
Jim
JD
I have a 72 type ‘O’ rearend with 28 spline axles and I’m wondering a couple different things 1) do I use chebby axles or the 68-70 Oldsmobile axles??? I know those splines are cut at 30 degrees. 2) can the 68-70 bop 8.2 gears be used in the 72 type’O’ axle??
I have a 72 type ‘O’ rearend with 28 spline axles and I’m wondering a couple different things 1) do I use chebby axles or the 68-70 Oldsmobile axles??? I know those splines are cut at 30 degrees. 2) can the 68-70 bop 8.2 gears be used in the 72 type’O’ axle??
As said above, you do not have a 1972 O-Type rearend.
My rearend housing has a ‘O’ on it?? I only wanted it get 1/2 studs but I couldn’t use original axles because too many access holes making it impossible to drill out 7/16 to 1/2. Don’t want to change the whole rearend. One more question for you guys while I have you, has anyone put wilwood brakes on this type of axle before? I can’t find a Direct fit, so I’m wondering if there’s another way to get them to fit?
If you are referring to the block "O" on the side of the center section, that identifies it as a 1971-1972 Oldsmobile version of the 8.5" 10 bolt rearend. It does not signify an O-Type, which has a 12 bolt cover.
Below is a picture of my 1971 8.5" 10 bolt showing the "O" and the casting number, which is the best method of identifying the rearend.
Yup that’s looks the same… man Oldsmobile really made things difficult. I guess I’ll just use the stock axles and wheel studs for now and try to figure out how to make the wilwood brakes work on the rearend. I put wilwood 6 pistons up front and the hubs came with 1/2 studs which I thought was great and wanted to match them up but I guess it wasn’t meant to be. The rear wilwood I have are for the bop rearend which uses a bigger bearing and I’m hoping I can just use the original bearing retainer plate to get them to work instead of using wilwoods retainer plate which is too big. There’s has to be a way because I see 71’s and 72’s all the time running them.🤷♂️
There are multiple companies that make axle shafts (and other parts) for the 8.5” 10 bolt rearends since they were used on multiple GM division vehicles for over a decade, so you should be able to easily find whatever parts you need.
