[Tim Corcoran]

Ok I have a question, are the backing plates and brake details (springs brake shoes etc.) interchangeable between a 10 bolt Pontiac rear end and a 12 bolt Chevy rear?

[Half-Inch Stud]

Yes, 10-Bolt plates, drums, T- bolts and brake stuff being far superior.

Use the 65-72 Big Car Pontiac Yoke on 12-Bolt for better results.

[ponchonlefty]

Originally Posted by Half-Inch Stud

Yes, 10-Bolt plates, drums, T- bolts and brake stuff being far superior.

Use the 65-72 Big Car Pontiac Yoke on 12-Bolt for better results.

just curious why would you change the yoke? the reason i ask is i have a 72 catalina.

[Half-Inch Stud]

Originally Posted by ponchonlefty

just curious why would you change the yoke? the reason i ask is i have a 72 catalina.

12-Bolt Yoke is for a U-Joint smaller and weaker than the GTO U joint.

Big Car U-joint and yoke are up to snuff, and fit the GTO Driveshaft.

[ponchonlefty]

Originally Posted by Half-Inch Stud

12-Bolt Yoke is for a U-Joint smaller and weaker than the GTO U joint.

Big Car U-joint and yoke are up to snuff, and fit the GTO Driveshaft.

good to know. im trying to absorb as much info as i can. thanks.

[Dragncar]

Originally Posted by Half-Inch Stud

12-Bolt Yoke is for a U-Joint smaller and weaker than the GTO U joint.

Big Car U-joint and yoke are up to snuff, and fit the GTO Driveshaft.

I have been beating on a T400 yoke out of the Oldsmobile station wagon for a long time now. It must be some sort of malleable iron but it stands up to 1.4 60 foots with T brake.

[Half-Inch Stud]

Originally Posted by Dragncar

I have been beating on a T400 yoke out of the Oldsmobile station wagon for a long time now. It must be some sort of malleable iron but it stands up to 1.4 60 foots with T brake.

I've seen some beefy TH400 yokes from Olds, and Caddy. Chevy Truck diddnt leave an impression. Hoop strength on TH400 Yokes are surely stronger than Rear Yokes with straps/bolts.

Ford 8.8 Rear seems to have the absolute best Yoke-.driveshaft yoke strength beacuse it is a pair of round plates bolted together. Large Bolts in shear to take the TQ.

My driveline is 1350 so these thoughts are to help those with such parts at hand.

['ol Pinion head]

Originally Posted by ponchonlefty

just curious why would you change the yoke? the reason i ask is i have a 72 catalina.

'65-70 P series big Pontiacs took a different pinion flange than comparable '71-76 Big Pontiac's. though they will fit on 12 bolt Chevy pinion (& seal), they are not something I use on 12 bolt builds, by using one, one creates another issue, driveshaft yoke compatibility.

GM oruginally built c-clip 12 bolt rears with 3 different pinion flanges (yokes):
-Most common was the style that accepted the small Chevy ujoint (Spicer1310)
-Next version accepts the larger spicer 1330 ujoint. Have only pulled these from rears original to '70 & 71 12 bolts from higher perf Chevelles & Elco's. They may have been used in '69 as well. The ones I've reinstalled used straps & 7/16 headed bolts.
Both the 1310 & 1330 flanges had small **** towards the outside of the pinion flange to locate the external clip type ujoint caps.
-last is the 12 bolt 3R version. The 3R is very similar dimensionally to the Spicer 1330 version, but a 3R ujoint uses internal clips, so flange is smooth to the end of the bore. The oem 3R pinion flanges for 12 bolts are not that easy to come up with used, & the average knowledge mechanic can easily damage the flange where the u-bolts go through. During 12 bolt builds with factory 3R 12 bolt pinion flanges I always set pinion depth without a crush sleeve & use a common 1310 pinion flange. Once pinion depth & backlash are exactly where I need, I disassemble & carefully reassemble with the 3R pinion flange.

[Bruce Meyer]

Originally Posted by Half-Inch Stud

Yes, 10-Bolt plates, drums, T- bolts and brake stuff being far superior.

Use the 65-72 Big Car Pontiac Yoke on 12-Bolt for better results.

Did they put 12 bolt rearends in 65-72 Big Car Pontiacs?

['ol Pinion head]

Originally Posted by Bruce Meyer

Did they put 12 bolt rearends in 65-72 Big Car Pontiacs?

Not in any US built big Pontiacs.

While the big car '65-70 Pontiac 8 7/8 P series rear & the '71-76 8 7/8 MP series rears are both 12 bolts, neither are a 12 bolt Chevy car diff.

[Bruce Meyer]

Originally Posted by 'ol Pinion head

Not in any US built big Pontiacs.

While the big car '65-70 Pontiac 8 7/8 P series rear & the '71-76 8 7/8 MP series rears are both 12 bolts, neither are a 12 bolt Chevy car diff.

So is HIS correct saying that the yoke off the Pontiac big cars will fit a Chevy 12 bolt car rearend? If so do you have an idea where to get one?

[bob prichard]

Originally Posted by Half-Inch Stud

Yes, 10-Bolt plates, drums, T- bolts and brake stuff being far superior.

Use the 65-72 Big Car Pontiac Yoke on 12-Bolt for better results.

I found a 65-72 big car Pontiac yoke for sale on ebay, from Frank’s Pontiac Parts. His ad states it has 28 splines, my Chevy 12 bolt has 30, so I don’t think that setup will work.

[Half-Inch Stud]

Originally Posted by bob prichard

I found a 65-72 big car Pontiac yoke for sale on ebay, from Frank’s Pontiac Parts. His ad states it has 28 splines, my Chevy 12 bolt has 30, so I don’t think that setup will work.

30-splines sounda like the Axle-Diff side gears. 30-Spline pinion-yoke for real?

[OG68]

I have a rear set of, if I remember correctly, 69 Vista Cruiser drum brakes.
The shoes are 2 1/2". Same as the front. They require the VC backing plates to work.
I ran them on my 68 for a number of years but had issues with the rear brakes locking up before the front drums. During the restoration I toyed with the idea of using them with a front disk setup but decided to keep the original drums with Muscle Car Brake Shoes.

And IIRC the 73-77 A body wagons had 11" brakes along with a select few Monte Carlos. Again, OPH can confirm.

[bob prichard]

Originally Posted by Half-Inch Stud

30-splines sounda like the Axle-Diff side gears. 30-Spline pinion-yoke for real?

Yes, unless I counted wrong. I also bought a Moser yoke for it with the same spline count.

['ol Pinion head]

Bruce, I have several '65-70 Pontiac 8 7/8 pinion flanges, back on after 7

[Bruce Meyer]

Originally Posted by 'ol Pinion head

Bruce, I have several '65-70 Pontiac 8 7/8 pinion flanges, back on after 7

PM sent

[lust4speed]

Originally Posted by Tim Corcoran

Ok I have a question, are the backing plates and brake details (springs brake shoes etc.) interchangeable between a 10 bolt Pontiac rear end and a 12 bolt Chevy rear?

Therefore another question. I'm pretty sure that the Chevy bolt 10-bolt center hole is slightly smaller than the BOP center hole and therefore the BOP backing plate bolts on to the Chevy, but the smaller Chevy 10-bolt backing plate won't flush up to the BOP axle housing. So is the 12-bolt center hole a little larger and the same as the BOP?

[Tim Corcoran]

I appreciate the additional info provided but am unsure if my original question was answered.

Are the backing plates and brake details on a Pontiac 10 bolt interchangeable with a 12 bolt Chevy rear? Thanks

[25stevem]

Yes, this string has gone off the rails a bit!

If you want a definitive answer then look in a Raybestos parts book and compare part numbers.

Look up a like a 68 A body Pontiac and then a 72 Camaro big block.

Just off the top of my head even though both rears could be had with 9.5” shoes, I do not think the backing plates are the same.