Factory build sheet
2021 GMC Sierra SLT
Build 3GTU9DED-M · 5.3L 8cyl · Four-wheel drive · Pickup
VIN positions 1 through 8 read 3GTU9DED and position 10 reads M. Those nine characters define this build. Position 9 and positions 11 through 17 differ on every car.
Every Sierra whose VIN starts 3GTU9DED and carries M in position 10 left the plant with the same engine, transmission, drivetrain and equipment listed below. We know of 13,872 of them.
- Decoded Jul 7, 2026
- 13,872 known VINs
- 320 listed for sale now
Factory specification
As filed by GMC with NHTSA for this build. Fields the filing does not record are left out entirely — a missing row means no recorded value, not a missing feature.
Engine
- Displacement
- 5.3 L
- Cylinders
- 8
- Engine model
- L84 - DI, ALUM, GEN 5, VAR 2
- Fuel type
- Gasoline
Drivetrain
- Drive type
- Four-wheel drive
- Brake system
- Hydraulic
Body & chassis
- Body class
- Pickup
- NHTSA body type
- TRUCK
- Doors
- 4
- Cab type
- Crew/Super Crew/Crew Max
- Series
- 1500
- Manufacturer
- GENERAL MOTORS LLC
Weight rating
- GVWR class
- Class 2F
- GVWR
- 7,001–8,000 lb
Gross vehicle weight rating is the loaded ceiling set by the manufacturer, not the car's own weight.
What this build asks today
Asking prices of live dealer listings decoded to this exact configuration — narrower than the trim-level figure, because every car counted here shares the same engine, transmission and drivetrain.
$35,492 median asking price · 351 listings · as of Sep 6, 2026
Low 2% of listings $24,995 Top 2% of listings $44,470
The same build, other model years
GMC used the VIN pattern 3GTU9DED for 4 model years. Nothing but the year changes between these pages, so the price gap between them is depreciation on an identical car.
How this VIN pattern is read
A 17-character VIN carries two kinds of information: what was built, and which one it is. This page is the first kind — the nine highlighted positions.
| Positions | Characters | What they encode |
|---|---|---|
| 1–3 | 3GT | GENERAL MOTORS LLC · World manufacturer identifier |
| 4–8 | U9DED | Model, body style, engine and restraint system |
| 9 | × | Check digit — computed per vehicle, not part of the build |
| 10 | M | Model year — 2021 |
| 11 | × | Assembly plant |
| 12–17 | ×××××× | Production sequence number, unique to each vehicle |
13,872 vehicles carry this build
Every VIN we have decoded to 3GTU9DED-M shares the specification above.
- 13,872 Known VINs
- 320 Listed for sale now
- 351 Priced listings
- $35,492 Median asking
Cars are filed by a fixed rule based on the VIN, so a car never moves between groups.
Neighboring configurations
Other factory configurations of the Sierra, each with its own build sheet. The set is fixed by the VIN patterns themselves, so it does not shuffle as prices or inventory move.
Keep going
Where this data comes from
Specification fields are decoded from the manufacturer's filings in the NHTSA vPIC database, keyed on VIN positions 1–8 and 10. We publish the filed values as they stand and leave out anything the filing does not record.
Prices are asking prices from 351 live dealer listings decoded to this build , last updated September 6, 2026 . They are what sellers ask, not what buyers paid.
Vehicle counts come from the 13,872 VINs of this build we have seen in dealer inventory. They are a sample of the road population, not a production figure.