G9Y ✓ Factory-verified

GMC · Regular Production Option

GVWR, 14,000 lbs (6350 kg)

Years 2025–27 Models 1 Factory citations 3

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Also documented for Chevrolet

Documented applications

Sierra HD — T1XX (2020–2027) →

• 2025–2027 ✓ Factory-verified

  only in: 3500 HD pickup and 3500 HD CC; dual rear wheels on the 3500 HD

  ⛭ GM factory document — 2025 gmc sierra 3500 hd retail and fleet fleet order guide rpo codes, p.1.

  ⛭ GM factory document — 2026 gmc sierra 3500 hd retail and fleet fleet order guide rpo codes, p.1.

  ⛭ GM factory document — 2027 gmc sierra 3500 hd retail and fleet fleet order guide rpo codes, p.1.

This page aggregates every documented appearance of G9Y in the GMC reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.