GM RPO Codes and Build Sheet
by VIN

What is a GM RPO code list?

GM records how every vehicle was built as a list of RPO codes (Regular Production Option). Each code is three characters and stands for one item, such as an engine, an axle ratio, a package or a paint color. When GM owners say “build sheet”, they usually mean one of these:

• The window sticker (Monroney label). It lists the trim, the preferred equipment group, each option with its original price, destination charge and total MSRP. This is the plain-English version.
• The RPO list. This is the raw code list, printed on the Service Parts Identification label on older vehicles and held in a QR code on newer ones. It’s more complete than the sticker but has no descriptions.
• The dealer invoice. GM doesn’t publish this by VIN, and we don’t have it.

Chevy and GMC build sheets from the original sticker

For Chevrolet and GMC (and Buick and Cadillac), the original sticker comes through a licensed window-sticker data partner. Before you pay anything, we run a free check that tells you whether a sticker is on file for your exact VIN. Coverage varies by model year, so we don’t promise one for every truck. If no sticker is on file, you’ll hear that before you pay. The report still has the decoded build data, full recall details and owner complaint counts as one PDF with a permanent link. Without the sticker, it can’t list option prices or a matched paint code.

When a sticker is on file, it’s included in the $9.99 Full Report and we parse it into a build sheet: standard equipment, optional packages with original prices, base MSRP, destination charge, total MSRP, EPA fuel economy and the assembly plant. The report also has the paint code and full recall details (what’s wrong, the risk, the fix), all in one PDF with a permanent link. It’s a one-time payment, with no subscription or account.

Free for every VIN: the NHTSA decode (year, make, model, trim, series, body, engine, drivetrain, fuel type and plant where reported), labeled “decoded data, not the original sticker”, plus the count of recall campaigns for that make, model and year and a link to nhtsa.gov to check open recalls for the exact VIN.

How to read GM RPO codes

A few patterns make an RPO list much easier to scan:

Example code	What it is
1LT, 2LT	Preferred equipment groups within the LT trim
Z71	Off-road package
L84	5.3L V8 with Dynamic Fuel Management
L87	6.2L V8
LM2	3.0L Duramax turbo-diesel inline-six
GAZ	Summit White paint (paint number WA8624)

Engine codes usually start with L. Codes are tied to model years: the LM2 diesel, for example, was replaced by the updated LZ0 in the 2023 Silverado 1500 and Sierra 1500. Always decode against the order guide for the right year, because GM has reused codes over time.

Common GM RPO codes and what they mean

These are the codes people ask about most. Meanings can shift between model years, so treat this as a guide and check the label or sticker for your exact vehicle.

Packages and equipment

Code	Meaning
Z71	Off-road package (trucks and SUVs)
Z51	Performance package (Corvette)
G80	Automatic locking rear differential
NHT	Max Trailering Package
Z82	Trailering package
JL1	Integrated trailer brake controller
K05	Engine block heater

Rear axle ratios

Code	Ratio
GU2	2.73
GU4	3.08
GU5	3.23
GU6	3.42
GT4	3.73
GT5	4.10

Engines

Code	Engine
L83	5.3L V8 (trucks and SUVs, 2014 to 2018)
L84	5.3L V8 with Dynamic Fuel Management (2019 and later)
L86	6.2L V8 (trucks and SUVs, 2014 to 2018)
L87	6.2L V8 (2019 and later)
LM2	3.0L Duramax turbo-diesel inline-six
L5P	6.6L Duramax turbo-diesel V8 (heavy-duty trucks)
LS3	6.2L V8 (Corvette, Camaro and others)
LT1	6.2L V8 (C7 Corvette, Camaro SS)
LT2	6.2L V8 (C8 Corvette)
LT4	Supercharged 6.2L V8

Paint

Code	Color
GAZ	Summit White
GBA	Black

A Z71 badge on the bed is easy to add, so the code on the label is what counts. The original window sticker names each package in plain English with its price, which is the quickest way to confirm what a truck really has.

Where are the RPO codes on a Chevy or GMC?

This changed with the 2018 model year.

• 2017 and older: look for the Service Parts Identification (SPID) label, usually inside the glove box. It lists the VIN, the RPO codes and paint information.
• 2018 and newer: GM moved this information into a QR code on the Certification label. GM’s own service publication says the label is on the driver-side B-pillar on all Buick, Cadillac, Chevrolet and GMC models, except the Corvette, where it’s on the driver’s door. Scanning it shows the VIN, model year, model, build date, vehicle order number, the RPO codes and the paint code.

If you’re at a lot, open the driver’s door, point your phone camera at the QR code and you’ll have the full code list in a few seconds. Paint is covered in more detail on our GM paint code page.

Is it a 1LT or a 2LT? Silverado and Sierra trims

The NHTSA decode usually gives the model, series and often the trim name. Common Silverado trims include WT, Custom, LT, RST, LTZ and High Country. Common Sierra trims include Pro, SLE, Elevation, SLT, AT4 and Denali.

The VIN alone won’t separate a 1LT truck from a 2LT, or tell you whether it has the Z71 package. For that, read the RPO list from the QR code or the sticker. Our trim lookup explains the limits of a VIN decode.

Contacting GM

• Chevrolet Customer Assistance: 1-800-222-1020
• GMC Customer Assistance: 1-800-462-8782

Have the VIN ready. The selling dealer can also look up the vehicle’s options. For the sticker itself, see the Chevy window sticker or GMC window sticker pages.

Sources

• GM TechLink: QR Code on Certification Label Offers More RPO Codes, GM’s technician publication on the 2018 label change
• Chevrolet owner support and GMC owner support
• NHTSA recall lookup, to check open recalls on your exact VIN