What is a GM build sheet?

A build sheet is General Motors' own factory assembly record for a specific VIN. It lists the RPO (Regular Production Option) codes the vehicle was built with — every package, individual option, paint and trim selection, axle ratio, and equipment group — exactly as it left the plant.

Where a window sticker is written for the buyer with plain descriptions and pricing, the build sheet is the underlying code-level truth. It's the most reliable way to confirm how a used Chevrolet, Buick, Cadillac, or GMC was originally configured, long after the original paperwork is gone.

Window sticker vs. build sheet

Newer GM vehicles (roughly 2020 and later) usually have the original window sticker PDF on file — the Monroney label with standard and optional equipment, fuel economy, warranty, and the full MSRP breakdown.

When a window sticker isn't on file, this tool automatically falls back to the build sheet: the list of RPO codes with their descriptions. Either way you come away with the factory record of how the vehicle was equipped.

RPO codes explained

Every factory option on a GM vehicle has a three-character RPO code — for example a specific paint, a tow package, a sunroof, or an audio system. These codes are also printed on the label inside the glovebox or spare-tire well.

The build sheet pairs each code with a readable description, so you can translate a glovebox full of codes into the actual packages and features the vehicle carries. That makes it easy to verify a seller's claims or settle exactly which options are factory.

Is 3TC the correct code for this feature?

Wheels & Tires · 2024 Chevrolet Suburban · 561 views · 4 replies

3TC — Tires, rear, 225/70R19.5 G 128/126 L BW HWY VAR1. This code identifies the factory tire specification, application, or spare-wheel equipment. Browse RPO codes →

Nicole C. Mar 4, 2026 · Illinois

The factory equipment list for my 2024 Chevrolet Suburban includes 3TC. My decoder describes it as “Tires, rear, 225/70R19.5 G 128/126 L BW HWY VAR1. This code identifies the factory tire specification, application, or spare-wheel equipment” I would appreciate a plain-English explanation and any model-year differences I should know about.

2 likes

4 replies

Jeff W. Mar 10, 2026

The wording may be abbreviated because these were originally production codes rather than consumer descriptions. “Tires, rear, 225/70R19.5 G 128/126 L BW HWY VAR1. This code identifies the factory tire specification, application, or spare-wheel equipment” is a reasonable plain-English reading, but the exact implementation should be verified for the 2024 model.

5 likes

Grace P. Mar 15, 2026

A window sticker is helpful for customer-facing option names, while the build sheet is usually more detailed. If they disagree, the vehicle-specific dealer equipment list can help connect the sales name to 3TC.

0 likes

Brooke G. Mar 20, 2026

Check the production month as well as the model year. Mid-year changes are one reason two vehicles with the same badge can have different hardware or descriptions.

1 likes

Jason M. Mar 21, 2026

This sounds more like a documentation mismatch than a decoder error. Different databases often shorten the same factory description in different ways.

5 likes

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