Hi all,

Picked these up for my 65 Cutlass and want to confirm these will fit my 65 rear end.






Regards,
Jim

 

At first glance it has a Chevy style crush sleeve but count the pinion splines where the yoke goes on and BOP is 27 splines , Chevy 10 bolt is 25 splines . , posi looks to be a 4 pinion BOP style

 

Chevy did not have 3.90 as a gear option it was 3.70 / 3.73 or 4.10 / 4.11
The posi looks like it was from 1970- 1972 see if the ring gear bolt holds are 7/16 or 3/8 inch
Then see if the ring gear is 3/8 or 7/16 left hand thread bolts.
A chevy crush sleeve will work for a BOP we have used them as they are stronger for the crush. because it is like 2.5 to 3 inches long
Also you can measure the height of the ring gear flange on the posi unit to see which series it is...JUST to make sure all the parts will jive. Jim

 

Hi,

So will it work if it's newer in a 65?

What are the rule of thumb measirements for each series carrier?

Regards,
Jim

 

YOU NEED TO SEE IF YOUR GEAR works with your carrier first. bolt size. then measure your carrier.
once the carrier has big 7/16 bolts it is hard to go back...they have machined sleeves but it gets VERY expensive to do all this
measure your flange down through a ring gear bolt hole to the table the way we have the carriers pictured.
There are so many distances...I am not listing them all. you need to be in the 2" range.

 

all 8.2 1965 - 1972 interchange in housings.
excluding buick 8.25" 1968 69 70 which have larger driver side carrier bearings

 

Hi all,

Supposedly the gearscand posi were in a car, the owner switch to a more highway friendly gear ratio. The guy I got them from had a 67 Cutlass and didn't realize the Olds only rear axle.

I will have to check it out farther this weekend, just want to verify things before I start ordering parts. The bearings on the carrier do match BOP numbers so 1 good sign.

Thanks everyone for the knowledge

Regards,
Jim

 

just measure the ring gear bolt holes on the carrier and the ring see if they are both the same. 3/8" x 24 thread count or 7/16 x 20 left hand thread.
Then measure the height of the flange that I showed a picture of.
Jim

 

Hi all,

Measures about 2" so looks like the correct series and never noticed it was a 4 pinion unit, had a 2 series 2.78-3.23 posi I bought years ago an comparing the 2 I can see the differences.

Gear is 3/8-24 and bolts have normal clearance on the carrier.



Left 4 pinion right 2 pinion




Don't mind the clutter.

Thanks again everyone for what to look for.

Regards,
Jim

 

That posi unit is a First design 6 bolt unit and has oiling window in the case under the bearing hubs. It is the weakest design BOP posi. with the smallest cross shafts. there was another in 66 67 68 design medium duty was 8 bolts and 6 coil spring .795 cross shaft diameter.... then the Super duty x cross shaft with 4 pinion gear design .795 shaft sizes and 3 coil springs inside of each other in the middle. the series you have with the 6 bolt design from the pictures if the super duty is 4 series 2 1/16" then the next step down is 2.93 - 3.23 then there is another on down which is 2.56 - 2.78.
At least you know it all matches.
Jim
JD race