Looking to change gears and add posi or in a perfect world find a year matching rear end set. Has a R2 axle now so wondering what my options were in adding a better gear (low to mid 3s and posi) or if anyone had a year correct axle for sale. I live in Georgia.

 

Create a parts wanted thread describing what you want. You could put a posi in your housing. But If your wanting to keep it original you may want the housing to have the correct code stamped into it. You might have to get one shipped. But there are members here who have what you need.

 

Additionally, there exist some value-add flavorful discussions pertaining to R2 upgrades - lots of them. Several searches & you'll gain some additional member inputs/suggestions, etc. IIRC, I think I read one caveat pertaining to cars which had A/C vs. those which did not have A/C relative to sizing of R2 gearing. At any rate, some additional searches might help to provide additional intel for you as well as what other members can/will provide. Here's one to consider...

R2 Axle Code - Recommendations?

 

Your 69 would originally have an O-Type rearend which is unique to Oldsmobile; with a 12 bolt cover and a 10 bolt ring gear. The gears and carriers are unique to the O-Type which was made for just a few years from 1967-1970 and therefore do not have a lot of aftermarket support.


I replied to your other thread with gear and carrier info. It’s best to have just one thread to keep all the info in one place.

 

Kenneth - OP's other thread was posted in Parts Wanted.

 

thanks I just created a parts wanted because someone here told me to. I saw your info and appreciate it. Looks like it might make sense to just find a year correct total rear end.

 

So what do you presently have? An O-Type, an 8.2” 10 bolt, or an 8.5” 10 bolt? If you’re not sure, post some pictures of the rear cover and the side of the center section. If it’s a 10 bolt rear, there are multitudes of parts available for gears and posi carriers. Not so much for an O-Type, though.

 

Been told an R2 is a 2.56 8.5 olds rear

 

The R2 code was used on several different rearend models, so that doesn’t identify which rearend you have.

How many bolts are on the cover of yours? Better yet, post pictures of the rear cover and the side of the center section and we can ID it.

 

 

 

The 12 bolt cover indicates it's an O-Type rearend.

 

I would open that up, see what is really inside . Before making any decisions

 

Good idea. The R2 axle tube stamp may not match what's in there. The edge of the ring gear will have the tooth count for the ring and pinion, so check that to see what ratio is actually in there, as well as verifying the type of carrier.

Here's a picture of the ring gear stamping for a 3.08 gear set (37 ring gear teeth divided by 12 pinion gear teeth = 3.08):

 

Was told it has posi but wasn't hooking up so opened up carrier and guy working on car told me it is a non posi 2.56 by counting.

 

Well that matches the R2 axle code, so at least you know what you have even if it's not what you really want.

 

A 3:42 ring & pinion for the Type-O is still made by Richmond Gears (PN: 49-0049-1), and you can get a posi from Supercars Unlimited (just be sure to pick the PN made for these aftermarket gears). Mine had a 2.78 open originally, and I never could find the axle code stamp, so I wouldn't loose sleep over that.