Unknown rear end code

[Tcupp]

I found the rear end code stamped on my 71 Monte. I looked at the tech section on the codes and could not find the last letter. Here is the code KDC 209 A. Does anyone know what the A is? It's a 12 bolt and I know it is the original rear end.

 

Thanks

[LS5]

This is all I got for now hope it helps...

Darren.

The rear axle identification code consists of at least a two letter prefix indicating the gear ratio, a letter for the manufacturer's identity, and three digits indicating the day of the year from January 1 and other codes as necessary. The identification code should be stamped on the bottom or font of right axle tube either adjacent to the carrier housing or about 8" - 10" inboard from the backing plates. The particular engine RPO code is listed in parentheses as found on buildsheets.

 

Example: RUC064(1 or 2) decodes to RU ~ 3.31:1, C ~ Buffalo, 064 ~ day of year starting with January 1 (the 64th day being March 5), 1 or 2 ~ shift (if present). See bottom of page for photo examples.

 

Casting Numbers:

12-Bolt Casting #3969278

10-Bolt Casting #3969277

 

The casting numbers/letters on rear end housings may have either a prefix or suffix of "N" or "NF" and no reason has been found yet why they may have one or the other.

Gear Ratio - First & second characters

 

 

 

Prefix

 

Axle Ratio

 

 

 

CF

 

3.31:1 ~ 12-bolt Positraction

 

 

 

CH

 

2.73:1 ~ 12-bolt Positraction (L48/350-4, LS3/330-4)*

 

 

 

CW

 

3.31:1 ~ 12-bolt (L48/350-4)*

 

 

 

GA

 

2.56:1 ~ 10-bolt (L65/350-2)*

 

 

 

GB

 

2.56:1 ~ Positraction

 

 

 

GD

 

2.73:1 ~ Positraction

 

 

 

GF

 

3.08:1 ~ 10-bolt

 

 

 

GG

 

3.36:1 ~ 10-bolt (base L6)*

 

 

 

GH

 

2.73:1 ~ 10-bolt (L14/307)*

 

 

 

GI

 

3.36:1 ~ Positraction

 

 

 

GN

 

3.08:1 ~ 10-bolt (L14/307)*

 

 

 

KD

 

2.73:1 ~ 12-bolt (L48/350-4)*

 

 

 

RU

 

3.31:1 ~ 12-bolt (LS5/454)*

 

 

 

RV

 

3.31:1 ~ 12-bolt Positraction (LS5/454)*

 

 

 

RW

 

4.10:1 ~ 12-bolt Positraction(LS5/454)*

 

 

 

 

 

 

Rear Axle Assembly Plant - Third character

 

 

 

Code

 

Assembly Plant

 

 

 

C

 

Buffalo, N.Y.

 

 

 

G

 

Detroit Gear & Axle

 

 

 

K

 

McKinnon Industries (GM of Canada)

 

 

 

W

 

Warren, MI.

 

 

Assembly Day - Day of the year, 000...365

 

Shift - 1 or 2 (or Day / Night) if applicable

[alex's72fgmc]

its a 2.73 :1 ratio rear end look in the tech info section for the rear axle decoding info i wrote up a while back covers all firsst gen montes

 

alex