I'm still scavenging parts off of the Cutlass junkyard find. I looked at the build sheet from the seats I bought last week and found that the car should have a posi unit. I went back today and sure enough, there's a posi tag on the rear and the glue outline under the trunk lid from where the posi decal used to be. The problem is, it's probably a 2.41 gear. Just wondered what it was worth and whether it's worth dragging home to resell...if the yard lets me have it cheap enough. The unit is complete drum to drum.

 

Worth scrap rate

 

IF you can get it for 50 bucks a usable 8.5 2 series Posi unit bare is still worth about a 100 without the housing and axles. Check ratio first it could be a 2.73 and would then be a 3 series carrier worth more. Whole rear end value as is about 200 and may have Bolt in Axles instead of C Clips so its a plus.

 

The build sheet is what tipped me off to lift the car. The build sheet lists it as a 2.41 ratio limited slip. The car is a 1976 Cutlass Supreme Salon. The limited slip tag is still on the inspection cover, so I'm asuming it's the original rear.

 

It is likely 2.41 gears, as listed on the build sheet I found in the seats. Does this mean it's a 2 series carrier and can't take 3 series gears, such as 3.21 and lower (numerically higher), or can I buy 3.21 gears and just put them in the 2.41 carrier?

 

I think it would work the same as using a ring gear spacer on a 3 series to run 4 series gears.

 

if it is 2.41 Yes a common ring gear spacer kit can be used and comes with the long bolts (Mr. Gasket).

The correct series goes as this ...

2 series carrier and gears on a 8.5 is, 2.41 and 2.56.

3 series on 8.5 is 2.73, 3.08. 3.23. 3.42. 3.73 up yada.

There is no 4 series carrier on the 8.5 ,

12 bolt Type C Chevelle type have 2, 3 and 4 series .

G80 is the common build sheet RPO code but does not determine ratio, if no ratio is listed then its it is the standard equipment ratio.

Did it flat out say 2.41 ratio on the build sheet ? Sometime you get RPO code like GT4 or GU4 that is ratio related

 

Yes, the build sheet showed an RPO code and "2.41 Ratio". I'm at work now, but I can post a pic of the build sheet later tonight.

 

Thats cool, its really just a matter if the junkyard will sell the rearend cheap

 

Here's the build sheet:

 

Cant open the link it goes to a 73-77 olds forum for the pic

 

here:

 

Ok, now I'm going to show my ignorance here...can I use the limited slip unit out of the 8.5 to make the factory rear in my 1985 442 a posi, or are the rear internals incompatible?

 

Thanks Yeah a GU1 code is 2.41 I see.

Your 85 442 should have a 8.5" 3.73 with 28 spline axles so Yes with a ring gear spacer kit your ring gear can go on the 2 series Posi and put back in , be sure your back lash and preload on bearings is close or same as it was when you take it apart.

 

Just sold one for $100

Was a 2.41 though