Okay, I found the CON2 which according to the site means a 2.56:1 Locking.

My questions:

1) I have found another number 87890 but it does not match my VIN. It is on the rear driver side of the housing. Is the VIN actually stamped somewhere on the axle or does this mean its not the original?

2) Locking: Does this mean POSI or Limited Slip? 2.56:1 with a 307 and 275/15 on the car. New ones at that so I haven't tried to see if it will make two marks...

3) There is also an F20 on the rear upper driver side of the housing. Didn't see that in the decoding anywhere, but may have missed it. Will go look some more while you smart guys review my list. (OKAY... before I posted I reviewed the page again... Maybe the F20 means June 20 casting date? This would be good I think. The engine is 0710 and the car is 07C. What do you think?)

===== Update =====
Okay, I read through the stuff on the site again and went exploring further and found some more numbers:

3969340 NF ? Driver front lower housing.
GM 70 Pass front lower housing. (Sounds just like the year.)
Then I was checking for missed places of cleaning and hit the one listed in the site:

C0C0710G1 Sounds like it is a one wheel 273.1 on 07/10 from Detroit Gear and Axle, day shift and not posi. Oh well... Being 07/10 though and the block also being 07/10 and the tranny having the VIN stamp it sounds like the original drivetrain?

I also dont understand why there is a CON2 on there in another location. But there is no tag for the use special grease anywhere and when I lift both wheels they spin in the opposite direction. I thought this meant limited slip but I guess not.

[This message has been edited by ItsMax (edited April 01, 2003).]

Casting marks is a raised number or code that is part of the mold that made the part in the foundry. AKA Casting Mark

Stamped codes are recessed codes that are hand stamped into the part at the machining plant (Chev G & A) to ID the application and dates of manf. AKA Stamped Code

So use the casting mark to get a general idea of usage but the stamped codes will always tell you what the application is.

CON2 is just a casting mark used in the foundry. It has nothing to do with the axle itself, just the housing.


C0C0710G1

COC - 1970 Camaro 2.73 Non-Locking (41-15)
07 - July
10 - Day
G - Chevrolet Gear & Axle plant
1 - built on the first work shift that day even though that may have been the only work shift.

The tern locking, posi and limited slip are often used to decibe a positraction rear axle. I can't tell you much nore on the difference but it has to do with the make of differental carrior (Eaton, Borg Warner etc and may just be a trade name?)

------------------
Mike

2002 Trans AM WS6 build #3124 - Pewter
2001 GMC Ext Cab SLT Z71 - Green

[This message has been edited by WS6 (edited April 02, 2003).]