72' 10 bolt cutlass rearend in a 66 cutlass.
Does anybody know if it is direct swap out. Wanting to use the later rearend because the parts are available.
Thanks for any help.
Kelly

 

yes but....

I am not sure if the yoke was the same because I had a custom driveshaft built. There were some 66's with a wide and some with a narrow rear. My car had the wide version so it was the exact width as a 72 8.5 rear I used. If your car has the narrower rear it will bolt up fine just remember the wheels will be out about 3/4 each side.

 

The 71/72 8.5 is a direct bolt in replacement rear. I do not know what Richard means by two different width 66 Olds rear ends. The Chevelle's used a narrower rear in 66/67 but all of the 66 Olds Cutlass rears I have seen are the same width as the 68-72 Cutlass. The u joint size is also the same.

 

Going what I have been told from more than one person. I was told some early 66's got the narrower Buick grey iron 8.2
I know the Chevelle change over rear has 67. I have owned early 67 with the 66 width and later one with the 68 width.

 

The 66/67 GM Olds parts book says that 66 F-85 B or P axle exc. V.C. or 442 OAI has a part # of 393246. V.C. being a Vista Cruiser that has a larger bearing and the 442 OAI or W 30 had a special hardened axle. I can't say that I've measured every 66 rear I've had but the ones I have are the same width. If I'm wrong,I apologize,just trying to help.

 

You will need a different length drive shaft.

Gene

 

As noted, it depends on what axle your 66 came with. If you have the older 8.2" axle with the flat pads for spring mounting, you will need to swap the springs that match the newer axle. If your 66 came with a Type O, then the later axle is a bolt-in. Yes, you'll need to carefully check driveshaft length.

 

The car is a 66 442 convertible, 4 speed car. I bought it recently. I do not know anything about the original rearend that was in the car. It has a either a 66 or 67 12 bolt 3:31 gear posi in it presently. I was thinking about pulling the rear end and build the later 72 rearend because I have everything. I would think the car should of had a O type rearend. Is there any chance the 12 bolt could of come from the factory. Maybe I should of wrote all this in the beginning and there would of been more facts come out about a 442 car rearend. Also the springs on my car look to have the pads that hold the later 72' car springs. I will probably bolt the housing in the car to make sure everything looks correct before going forward.
Thanks for all the help.
Kelly

 

Is the 12 bolt a Chevy? with a 3.31 gear,that sounds like a Chevy. The O type Olds was available in any 66 or 67. Most think the 12 bolt O type Olds was available starting in 67 but they were available starting in 66. Most of the performance axles in 66/67 were the B/P axle. The 66 W-30 cars had the P axle. I do not know of any Olds 12 bolt with a 3.31 gear,I could be wrong but don't think so. However,there's one exception to the Olds having a 3.31 gear. If it's a Canadian built 68/69 with a C or Chevy axle,they were available with a 3.31 gears. I can't find any mention of an Olds or O type having a 3.31 gear.

 

sorry about that it is a rearend out of a chevelle, it has a code CF. Which is all corect for a 66' 67' posi 3:31 gear.
Kelly