General Motors Gmc SIERRA HIGH 25
Built: 1979 · Series: SIERRA
More machines from model year 1979
Not the right version? The data comes from vehicle registers holding many near-identical versions side by side. Photograph the data plate — we read make and type from it. Open the scanner e-mail address required
GMC Sierra – from trim name to full-size pickup: six- and eight-cylinders of 3.0 to 7.4 litres, 1,720 to 2,763 kg unladen weight, SLE, SLT, AT4 and Denali trim lines
At GMC, Sierra was initially, from 1971, only the name of the upmarket trim line on the C/K pickups – Sierra Grande denoted full equipment, Sierra Classic the simpler level. Only in 1988 did Sierra become the standalone model name of the full-size pickups, which GMC has since offered alongside the technically largely identical Chevrolet Silverado. This page gathers both eras, from the older C/K Sierra trims of the 1970s and 1980s to the current generations with the SLE and SLT trim lines, the off-road AT4 and AT4X variants and the Denali luxury version.
Read on 3 more paragraphs
The register lists here 25 versions with six to eight cylinders and 2,977 to 7,440 cm³ displacement, unladen weights from 1,720 to 2,763 kg, gross vehicle weights from 2,358 to 3,500 kg and widths from 1,850 to 2,550 mm.
The Sierra, together with the Silverado, is among the best-selling pickups in North America and forms the counterpart there to the Ford F-150; in Europe it remains a rare import, adapted for local road use by specialised converters.
Buying used, on Sierra pickups the condition of the frame and suspension, rust in the rear wheel arches and load bed, the function of the automatic transmission and, where fitted, the four-wheel-drive clutch, and on V8 engines with cylinder deactivation their responsiveness all count; spare parts are available through US import trade and cross-brand GM specialists.
Sources: SpecCodex register, model data: GMC Sierra, GMC (General Motors, Hersteller)
Technical data
Engine
| Cylinders | 8correct |
|---|---|
| Displacement | 5,700 cm³correct |
Dimensions and weights
| Width | 2,050 mmcorrect |
|---|---|
| Wheelbase | 3,310 mmcorrect |
| Unladen weight | 2,345 kgcorrect |
| Gross vehicle weight | 2,903 kgcorrect |
Drivetrain and chassis
| Wheels | 4correct |
|---|
Frequently asked questions
How much does the General Motors Gmc SIERRA HIGH 25 weigh?
The unladen weight is 2,345 kg.
What is the gross vehicle weight of the General Motors Gmc SIERRA HIGH 25?
2,903 kg.
What engine does the General Motors Gmc SIERRA HIGH 25 have?
8 cylinders, 5,700 cm³ displacement.
When was the General Motors Gmc SIERRA HIGH 25 built?
Production years: 1979.
What to check before buying
- Check the hour meter against the service records — a replaced instrument is the most common gap.
- Compare the data plate and chassis number with the papers.
- Check the weights in the papers against the figures here — attachments change them.
- Ask about parts availability for this build year — the running costs hang on it.
A general list for this type of machine — no substitute for an inspection or an appraiser.
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This page carries 9 individual figures for this model. They come from 2 recorded sources; every figure can be traced there. What we cannot document is not here — we leave gaps open rather than estimate them.
The technical data on this page comes from official vehicle registration records (RDW/Traficom), not from the manufacturer.
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Other models in this series
GMC SIERRA 1500
GMC SIERRA 1500 AT4X
GMC SIERRA 1500 DENALI
GMC SIERRA AT4
GMC SIERRA DENALI
SIERRA 1500
SIERRA 1500 4WD
SIERRA 1500 AT4
SIERRA 1500 CREWCAB SLE
SIERRA 1500 DENALI
SIERRA 1500 SL
SIERRA AT4
Sources: RDW — Dutch national vehicle register (retrieved August 2026) · How we check the data
Van in 3D section
Turn the model, look inside and click an assembly — each one is explained.
