RPO Codes

I used to collect General motors Regular Production Option (RPO) codes. I haven't been collecting them since 2002. There are probably more complete lists of RPO codes out there than what I've got here.

Some of these may be out of date.  Some might even be inaccurate.  If you have RPO codes to add or update email me.

There are no "o" or "s" RPO codes as the letters are too similar to a number "0" and "5".
Here are some of the more common RPO codes:

Gear Ratios:
Code    Ratio
GU2     2.73
GU4     3.08
GU5     3.23
GU6     3.42
GT4     3.73
GT5/GT8 4.10

G80  GM Gov-Loc locking differential.  Sometimes it was a clutch-type limited-slip.  Once in a while it was a zexel-torsen.  The only way you’ll know is if you pull the differential cover off and look.

 Z75   Front quad shock absorbers.

Engine RPO Codes and VIN cross reference

Use this for cross-referencing VIN to RPO codes

E85 vehicles:
• 2000-2002 S-Series pickups with 2.2L (VIN 5- RPO L43)
• 2002-2005 full-size pickups and utilities with 5.3L (VIN Z -- L59)
• 2006 Chevrolet Avalanche, Silverado, Suburban, Tahoe with 5.3L (VIN Z -- RPO L59)
• 2006 Chevrolet Impala, Monte Carlo with 3.5L (VIN K -- RPO LZE)
• 2006 GMC Sierra, Yukon, Yukon XL with 5.3L (VIN Z -- RPO L59)
• 2007 Chevrolet Avalanche, Suburban, Tahoe with 5.3L (VINs 0, 3 -- RPOs LMG, LC9)
• 2007 GMC Yukon, Yukon XL with 5.3L (VINs 0, 3 -- RPOs LMG, LC9)
• 2007 Chevrolet Impala, Monte Carlo with 3.5L (VIN K -- RPO LZE)
• 2007 Saturn Relay, Buick Terraza, Chevrolet Uplander, Pontiac Montana SV6 (Canada Only) with 3.9L (VIN W -- RPO LGD)