Rear end ID
 

Double-checking the ID on my rear end after removing the driveshaft. Back side looks like a typical 8.5 10-bolt GM, but the driveshaft side is less certain, no U-bolts, no "straps," just four 7/16" bolts. Any help ID'd this is appreciated.

Re: Rear end ID
 

I see the ears on top of the center section for the upper suspension arms used in passenger cars. I'm going to guess that your wheel stud pattern is 5 x 4.75? The pinion flange looks to be designed for a CV joint.

Re: Rear end ID
 

Bolt pattern is 5x5. The flange doesn't match up with anything I've found online or in shop manuals. I'm swapping out my 350TH transmission for a 4-speed, and I'm planning on reusing the driveshaft, so it doesn't matter all that much, but I'd love to know what it is!

Re: Rear end ID
 

Looks like may be Oldsmobile. They had a 12 bolt (ring gear bolts) with a 10 bolt rear cover that used a flange like that. Looked at a C20 last year with a 455 in it and it had the Olds rear in it, It was 5 on 5. Had that flange with a 3" thick spacer in it to make the drive shaft work.
Jimmy

Re: Rear end ID
 

Thanks. Swapping in a beefed-up Saginaw 4-speed, so the measurements should stay the same.

Re: Rear end ID
 

Beefed up Saginaw!
Where would you get one of them?
What’s the first gear ratio in it?

Re: Rear end ID
 

2.84. Rebuilt by someone I know, so I'm keeping my fingers crossed. I know the warnings about Saginaws not being able to handle much, but I'm not going to be doing any drag racing!

Re: Rear end ID
 

As long as you don’t sidestep the clutch pedal and treat it nice it’ll last.
I ran a 3.11 gear one behind an L34 396 and an LS6 454 for awhile.

Re: Rear end ID
 

That's encouraging! I'm running a 400SBC.