I did a search for a thread on RPO codes but couldn't find anything on them.

I ran my RPO codes through RPO Codes.com- GM option codes,GM rpo codes,General Motors options and was able to identify most of the codes listed for my truck. However there are five I couldn't find and was wondering if anyone here could help:

DL3, HVY, NT9, PDD, ZGK

Also, was wondering if anyone could tell me the capacity of the HYDRO-MATIC 4L80-E transmission.

The code GT5 indicates I have a 4:10 rear-end ratio, but in parenthesis it says "Dup with GT8" anyone have an idea of what that means. I couldn't find anything about the front differential so I'm assuming it is also a 4:10 ratio and that maybe what "Dup with GT8" means.

Okay, one last thing, G80 means Axle Positive Traction, Limited Slip. It doesn't indicate front or rear, so I'm assuming it means both. The reason I assume this is because all the other codes in this range specifically state "REAR" and no where in the list of codes is there any indication of what the front end is.

Thanks
73

 

Found this site:
GM-Trucks.com | RPO Code Lookup

Copy and paste from the site:

DL3 Mirrors, outside heated power-adjustable, power-folding and driver-side auto-dimming
DL3 Mirrors, outside heated power-adjustable, power-folding and driver-side auto-dimming, color-keyed
DL3 Mirrors, outside heated power-adjustable, power-folding and driver-side auto-dimming, body color
DL3 Mirrors, outside heated power-adjustable, power-folding and driver-side auto-dimming, body-color
DL3 Mirrors, outside heated power-adjustable, power-folding and driver-side auto-dimming, Black
DL3 Mirrors, outside rearview, power folding, power adjustable, heated, color-keyed
DL3 Mirrors, outside rearview, power folding, power, heated, color-keyed
DL3 Mirrors, outside rearview
DL3 Mirrors, outside rearview, power folding, power, heated, Black
DL3 MIRROR O/S LH & RH, REMOTE CONTROL, ELECTRIC, HEATED, POWER FOLDING, TURN SIG IND, LT SENSITIVE, COLO

HVY Identification 2 Inch Body Raise, H.D. Model
HVY IDENTIFICATION 2-INCH BODY RAISE, H.D. MODE


NT9 Emissions, Federal, Tier 2 Phaseout
NT9 EMISSION SYSTEM FEDERAL, TIER 2 PHASE-OUT

PDD Rear Power Package
PDD Convenience Package #1
PDD Convenience Package 2
PDD 1LT Convenience Package
PDD 2LT Convenience Package
PDD Convenience Package 1
PDD Comfort and Convenience Package
PDD Convenience Package
PDD Enhanced Convenience Package
PDD Driver Convenience Package
PDD Work Truck Convenience Package
PDD Floor covering, color-keyed carpeting
PDD Floor covering, color-keyed both carpeting and floormats
PDD Floor covering, color-keyed both carpeting and mats
PDD CONTROL SALES ITEM NO. 121


ZGK Tire, spare LT245/75R16E, on-/off-road, blackwall
ZGK Tire: Spare LT245/75R16E BL R/PE ST OOR
ZGK Tire Spare LT245/75R16/E BW R/PE ST TL 00R 120Q
ZGK TIRE SPARE LT245/75R16/E BW R/PE ST TL OOR 120Q

Transmission:
Hydra-Matic 4L80-E 4-spd Transmission Tech Article by BillaVista - Pirate4x4x.com

Dup with GT8 is a duplicate code
<table class="product_table" id="product_table" border="0" width="66%"><tbody><tr height="13"><td>
</td> <td colspan="3" height="13">
</td> <td>
</td></tr></tbody></table>Cannot answer the G80 code you will have to look at the front axle for codes