I was scroungin' parts at the pick a part this afternoon...I found an Omega that looked fairly old, so I found the sticker on the drivers door and it said it was built in 10/74. I got a little excited thinking it would be worth building up for one of the Camaros. Inside the car I found a cope of the registration. It said it was a 1975 model year. I looked under the car and it is definately an 8.5 10 bolt. My question is: What is the difference between a 74 and 75 8.5" 10 bolt rear? And is there any way to know for sure if it's gonna fit in a 1st gen Camaro? Measure from mounting plate to mounting plate and from backing plate to backing plate?
Thanks-Dano:beers:

right Dano, those 2 numbers tell the story. 75 should be good to go, thru 76 even I think.

Pick that part, Dano! Up to 79 X-body is the right width, it's just that 76 is when the 7.5 started showing up. Mine came out of a Burnished Turd 75 Omega. Fits no problem.

If you're trying to do it cheap, grab the driveshaft too, or at least look at the rear U-joint. If it's a 1310 (clips in the ends) you may get away with your driveshaft. If it's a 3R (clips are on the inside edges of the yoke, not visible from the side), you may want to try to use the X-body shaft. Either way you may need to have the driveshaft shortened a little.

I got a 3R because then I could get a 1330/3R hybrid joint to match the front 1330 for my TKO. I'm not sure if there is a 1310/3R hybrid to match factory 1st gen joints.

Thanks for the replies guys. It's also a disc brake car w/a.c.! i did some research on the x-body site and found that a sure fire way to tell is: If the steering box is behind the crosmember, then it should be a direct bolt in, if it's in front of the xmember, it's comperable to a 2nd gen Camaro type setup... I think I will get up early and start yankin' parts off this thing! If nothing else, I can always sell the disc brake stuff and a.c. parts on Craigslist or ebay. I've been waiting a while to find one of these. The car seems to have only 80k original miles. I'll measure the perches and plates too just to be sure. Thanks again!
Dano

I went down to the yard this morning and looked at the Omega...The steering box is in front of the cross member, and when I measured the perches and plates, they would fit a 2nd gen car:sad: SOOO, I cracked open the diff cover and saw that it was not a posi anyway. The search continues...

Dano

It should have been right for the first gen, but you can't tell about these things. I have seen them both ways. It is always best to measure first. The spring perches should be 42 1/2 inches center to center.

Well, I had the day off today, so I went back to the junkyard and this time I took a length of wood that I cut to 42 1/2" long. I measured middle of perch to middle of perch and BINGO! It IS the right length. I got the axle out in a couple hours and lugged it up to the truck. 80.00 for everything. I would have snagged the driveline, but it looked dented up pretty bad... Now I need to degrease and decode the thing. Hopefully this thing will work for the 69 car so I don't have to rely on the old conical 4-pinion thing I was gonna put in the car ;)

Dano:beers:

Great! Let me know if you need parts.

The ring gear is 3.08 and there is no posi unit...I think I will keep the gearset because I do alot of freeway driving/cruising...I WILL be needing a posi that will work with this set up. Too bad we live so far away Freddie, or I would just bring it to ya and let you work your magic on it ;) I'll P.M. you re the posi unit...
Dano

I have a 3.08 in my 67 with a TH350 and 327.Its a good all around gear.

You could install a Richmond Power Trax. You wouldn't have to remove the differential to install it. You can do it in about an hour.

Get an Eaton posi from Freddie.It isnt hard to change the diff. unit.All you need is a dial indicator and a torque wrench.

Plum, I talked to Freddie today about everything... Real nice guy with loads of info on these rear axles! :thumbsup: After I do some reading and save up a few bucks I'll go for the Eaton, besides, I like to learn new things! Thanks again for the replies!
Dano:waving:

Dan,
Here is the link to the nastyz28 post that I was telling you about. If you have any questions let me know. http://www.nastyz28.com/forum/showthread.php?t=19773&highlight=install+posi
I tried to send you an email, but it was blocked.