NZZ is the RPO code for GM’s off-road skid plate package — steel or aluminium shields under the front of the truck protecting the oil pan, the transfer case and the front differential from rocks and stumps.
It is usually bundled with Z71, and GM’s own documentation says as much. But it is its own code, it can appear without Z71, and Z71 has meant different things in different years — so NZZ on the label is the specific evidence that the plates were fitted.
Where NZZ is documented
| Year | How GM described it | Source |
|---|---|---|
| 1998 | “Sales package, skid plate, off road” | GM option master |
| 2000 | “Off-road skid-plate package” | 2000 Chevrolet C/K & Silverado Truck Restoration Kit |
| 2007 | “Off-road skid-plate package” | 2007 Chevrolet Silverado Classic Truck Restoration Kit |
| 2016 | “Skid plate, off road — included with Z71” | 2016 Special Applications: Snowplow Prep Package |
| 2021–2023 | “Skid plates” | GM Upfitter police and special-service specification guides |
| 2025–2026 | “Skid plates” / “skid-plate package” | GM Fleet order guides; 2026 Silverado 9C1 spec guide; GM Canada eOGLD |
Twenty-five GM-sourced records spanning 1998 to 2026. The 2016 wording is the one that settles the Z71 question in GM’s own words.
What the plates actually cover
GM’s descriptions say “skid plates” and stop there, so the component list below is what you will physically find rather than something we can cite to a document. Check your own truck before assuming.
- A front shield ahead of and under the oil pan and steering linkage
- A transfer case plate on four-wheel-drive trucks
- On some configurations, a front differential shield
- On some years, a fuel tank shield
What NZZ does not include on any truck we have documents for is rocker protection or a rear differential cover. Those are aftermarket.
NZZ and Z71 are not interchangeable
| NZZ | Z71 | |
|---|---|---|
| What it is | The skid plates | The off-road package |
| Scope | One component group | Shocks, badging, and varying content by generation |
| Can appear alone | Yes | Yes |
| Contains the other | No | Usually — GM states this for 2016 |
A Z71 badge on the bedside is a sticker. NZZ on the label is a build record. If you are buying a truck for trail use, the label is the one that matters.
How to check yours
- Decode NZZ for your model year, and run the whole label so you see whether Z71 and NQH are there too.
- Get under the front of the truck. Factory plates bolt to threaded bosses in the frame and crossmember, and the bolt heads are usually still painted body colour or black. Aftermarket plates use clamps, U-bolts or drilled holes.
- Look for damage while you are there. A plate that has taken a hit can be bent into whatever it was protecting.
What NZZ does not tell you
- It is not suspension. Off-road shocks and springs are separate content, and on many trucks are part of Z71 rather than NZZ. The standard suspension code is Z85.
- It is not a locker. That is G80.
- It does not mean the plates are still on the truck. They are the first thing removed for an oil change and the first thing forgotten afterwards.
Sources
- 2000 Chevrolet C/K & Silverado Truck Restoration Kit, GM Heritage Archive
- 2007 Chevrolet Silverado Classic Truck Restoration Kit, GM Heritage Archive
- 2016 Special Applications – Full Size K Series (4×4): Snowplow Prep Package, GM Upfitter
- 2021–2023 GM Upfitter police and special-service package specification guides
- 2025–2026 GM Fleet order guides; 2026 Silverado 9C1 spec guide; GM Canada eOGLD
- GM VPPS option master, November 2002
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