The shock plate and mount are not correct for a factory multi shock plate. They are not mono shock plates either. With the disc's who knows what is going on... It very well could be a 1st gen Camaro or 3rd gen Nova rear end though.

 

The rear end is a 8.5 out of something else. If the over all width is 60 inches then it's a Nova rear end. If the width is 61 inches then it's a 2nd gen Camaro rear end. The Nova spring perches are in the correct location for a 1st gen Camaro, but the 2nd gen Camaro perches are 2 1/4 inches too far apart. If someone tried to squeeze a 2nd gen rear end in it then that may be part of the problem. The lower plates with the shock mounts have been modified, so that may be the problem with the shocks.

 

I tried measuring the width to the square mounting plate to mounting plate at 52”
You can see the shock squeezed in really hard at the leaf on the left side.
Is this is a good rear to have?
It has Willwood disc on front and rear. Btw. The car is a 69

 

The 8.5 is stronger than the original 8.2. Take the wheels off and measure the width. You can't use backing plate measurements. They are useless.

 

From where to where am I measuring from ?

 

As big gear head said, its an 8.5" 10 bolt. You can easily identify it by those two square lugs on the bottom of the differential housing. Is it a good rear end to have? I think so and I was pleasantly surprised when I found out mine had one. They are stronger than the 8.2" unit and I've even seen some say they can be nearly as strong as a 12-bolt, assuming good components are used of course.

 

I was getting pretty bummed about this find.
I was just gonna scrap it a buy a 12 bolt. But with that encouraging news. It might pay to get the shock mounts fixed and stuff in a good planetary set up?
How do I fixed the shock mounts?
I have no reference to go by?
Thanks for you help!!!

 

Well, are we sure that the shock mounts need to be fixed? They may not be stock but are they causing a problem? It looks close in the picture, but if they are not interfering with the leafs or anything else, do they need to be changed?

 

Detroit speed has some nice looking multi leaf shock plates. If you have a 1967 Camaro you will need a left and a right plate. If you have a 1968-69 with one shock ahead and one behind the axle you will need two RH plates.
Detroit Speed Camaro shock plate

 

Bruce1968- if you blow up the picture of the left shock. It is getting crushed by the leafs

 

Here’s some number

 

Numbers look like C716, 1235542

 

Also found this on the right tube P.W.C

 

Bubba, These links should help you identify what you have.

1967-69 Camaro Drivetrain Decoding

First-Generation Camaro Research and Restoration Data

camaros.org

NovaResource - Nova Rear Axle Codes

 

I have an opportunity to buy a 1968 12 bolt with a spool, 4:11, C clip eliminators, 30 spline and measures 53 1/4 from backing plate to backing plate for $1500. It’ll need rebuilding.
OR
Take the money and invest in the 8.5 I already have.
what’s best to do

 

I have an opportunity to buy a 1968 12 bolt with a spool, 4:11, C clip eliminators, 30 spline and measures 53 1/4 from backing plate to backing plate for $1500. It’ll need rebuilding.
OR
Take the money and invest in the 8.5 I already have.
what’s best to do

I'd pass on that 12 bolt unless you need a lot of strength for big HP and want to drag race. You're probably looking at at least another $1500 to get is setup right. A spool on the street sucks, IMO, and unless you have a good overdrive, 4.11s are pretty low if you ever want to get on the highway. I had the same setup in my 10 bolt when I got it and once a pulled it all out for 3.42s with a Trutrac and totally changed the character of the car and made it much more fun to drive. But, I don't know what it will cost you to fix the shock mounts on the 10 bolt you have.

 

You need to stop using backing plate measurements. They are not accurate. Over all width is what you need to be measuring. The first gen Camaro is 60 inches and the 2nd gen Camaro is 61 inches. Measure from where the wheels mount. The first gen Camaro spring perches are 42 1/2 inches center to center and the 2nd gen spring perches are 45 1/4. You need to measure this on your car and see if the spring perches are in the correct position or if someone pried the springs apart and stuffed a 2nd gen rear end in it.

 

I have Wilwood discs on the rear, so I think if I did it your way it would be wrong.
From center of perch 43 5/8
Inside of spring to spring 52
From inside of disc to disc 39 1/2

if I spin the axle one rotation. I get 1 and an 1/8th revolutions at the yoke.

 

Well I couldn’t wait so I pulled the cover. I think it’s a 308. Can you guys tell if it’s a Posi unit or just open by looking at the picture.

 

What size wheels and tires are on the rear? You've got some custom "made it fit" rear end setup and your numbers don't work! From inside of disc to inside of other disk can't be less than center of spring to center of other spring... Best to start over, use the picture Al posted and give the A & C measurments. C being the pad where the wheel mounts and has studs coming out of it.

 

That's a Governor Lock from a truck. It's OK for a stock truck, but junk for high performance use. I'd replace it with a Eaton Posi or Eaton Truetrac. Check your axles and see if they are 28 or 30 spline. You still need to check the over all width of the rear end. Even with disc brakes the over all width is going to be within 1/4 inch. Backing plate measurements and disc to disc measurements mean nothing. 43 5/8 center to center on the spring perches isn't right unless this is a truck rear end and someone welded them on in the wrong place, which might be part of your problem.

The 3.08 gears are from 1973, and the 8.5 wasn't used in the truck until '82, so someone has put this rear end together from parts.

Pass on the 12 bolt. You don't want to run c clip eliminators on the street. They just cause problems.

 

A= 43 5/8 that is center or perch to center of perch.
C= 58 1/8 or 1/4
Rim is 20x 9.5, bs 5.25
Tire is 275-35-20

 

A= 43 5/8 that is center or perch to center of perch.
C= 58 1/8 or 1/4
Rim is 20x 9.5, bs 5.25
Tire is 275-35-20

So the spring pockets are off by 7/8" and would provide more shock clearance if moved inward, your springs would like it better too. Then at 58 1/4 your wheels are mounting an inch inward on each side over stock so the tires should be fairly tight against the inner fender. Most run a 5.5" bs with a 9.5" wheel and it's close. Your mounting pad and less backspacing still pushes the inside wheel and tire 3/4" closer to the inner fender and shock. You should have tons of clearance on the outer fender lip.

If you keep that axle housing I would move the spring perches to the proper location and use a thin wheel spacer or wheels with a little less back spacing to center the wheel in the fender well. Then you can get the proper multi-leaf shock mounts and a posi carrier. Or start looking for a stock 3rd gen Nova 8.5 with posi and the gears you want. I think the cost might be a wash and you already have. Disc brakes on what you have should work on the Nova axle housing so really look at what you have condition wise.

 

Big Gear Head- To me it looks like the 8.5 is gonna be nothing but headaches and costly to replace the unit, gears, bearing and redo the perches VS. the 12 bolt getting a new Posi, gears and bearings. Seems to be a better bolt in w/o too much guessing.
What are your thoughts?

 

Here’s the 12 bolt for sale

 

If the rear end that is in the car now is 58 1/4 inches wide then it's about 2 inches narrower than a stock Camaro rear end, which is 60 inches. The 12 bolt will be 60 inches. That's going to push the wheels and tires out about an inch on both sides. I'm guessing that you don't have that much room.

The 12 bolt is set up for drag racing. Even if you put in a new Eaton Posi, new gears and bearings, you still have the c clip eliminators, which don't work well on the street, and are a big NO for auto cross or high side loads. It doesn't even have the spring perches on it. That's not the right rear end for you.

 

I'm still wondering what this rear end came out of. I don't know of any 8.5 that is that width other than the Buick GN rear end. It could be a narrowed truck rear end. I'd take a close look at it and see how the welds look. If it looks like a crappy job then you might want to consider another rear end. I still think that 12 bolt is wrong for what you have, unless you want to go drag racing full time with this.

 

Oh wow. I just went back and looked at the pictures again and I believe this was a GN rear end. I can see where the upper control arm eyes have been cut off. What a shame!