Used GMC Engines For Sale

1,973
verified GMC engines
Trustpilot
Customer Reviews
Up to 3 yrs
extended warranty available
Photos before
shipment

Used GMC Engines For Sale

1,973 verified used GMC engines in stock across 1990–2024 — 5.3L EcoTec3 V8, 6.2L L86/L87 V8, 3.6L LFX V6, 6.6L Duramax Diesel V8 and more. Every unit is VIN-matched to your vehicle, ASE-tested by certified technicians, photographed before shipment, and backed by a warranty (standard term by model year, extended coverage up to 3 years) plus 30-day money-back. Free freight nationwide.

●
Warranty On Every Unit
●
Photos Before Shipment
●
ASE-Tested & Verified
●
Free Nationwide Shipping
●
30-Day Money-Back
●
Secure SSL Checkout

Browse GMC Engines by Year

Pick your model year — every year page is built from live inventory and lists the GMC models and engine families in stock for that year with the count of each.

20242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999199819971996199519941993199219911990

GMC Engines We Cover

Real GMC engines from our warehouse, tested and ready to ship. GMC shares its entire engine catalog with Chevrolet — a unit pulled from a Silverado is frequently the correct part for a Sierra, so the RPO code and generation matter far more than the badge on the tailgate.

Used GMC 5.3L EcoTec3 V8 engine
5.3L EcoTec3 V8
Sierra 1500, Yukon, Yukon XL, Denali (1999-present). GM's high-volume light-duty V8 — LM7, LMG, L83 and L84 generations are NOT interchangeable.
Used GMC 6.2L L86/L87 V8 engine
6.2L L86/L87 V8
Sierra 1500 Denali, Yukon Denali, Yukon XL Denali (2014-present). GM's premium light-duty V8 — direct injection, 420 hp class; L87 adds Dynamic Fuel Management.
Used GMC 3.6L LFX V6 engine
3.6L LFX V6
Acadia, Terrain, Canyon (2012-present). GM's DOHC HFV6 — the transverse Acadia/Terrain application differs from the longitudinal Canyon.
Used GMC 6.6L Duramax Diesel V8 engine
6.6L Duramax Diesel V8
Sierra HD 2500/3500 (2001-present). LB7, LLY, LBZ, LMM, LML and L5P generations — injector and emissions history is the thing to ask about.
Used GMC 5.7L 350 Small-Block V8 engine
5.7L 350 Small-Block V8
C/K trucks, Sierra, Yukon, Suburban (1990s era). The classic GM 350 — throttle-body and Vortec heads differ; parts availability is unmatched.
Used GMC 6.0L Vortec V8 LS engine
6.0L Vortec V8 LS
Sierra HD, Savana 2500/3500, Yukon XL HD. LS-family heavy-duty V8 — the 2500/3500 workhorse, often paired with the 4L80E or 6L90.
Used GMC 4.3L Vortec V6 engine
4.3L Vortec V6
Sierra 1500, Sonoma, Jimmy, Safari, Savana. 90-degree V6 derived from small-block V8 architecture — the EcoTec3 LV3 is a separate later generation.
GMC engine inventory row
More GMC Engines
Plus 5.3L Generation IV LS, 2.8L Duramax (Canyon), 2.5L Ecotec, 4.8L Vortec, and 2.7L Turbo — text us your VIN.
Trustpilot

Why Buy a Used GMC Engine from Auto Power Source

GMC is General Motors' truck division, and its engine catalog is the GM truck catalog: the 5.3L and 6.2L EcoTec3 V8s in Sierra and Yukon, the 6.6L Duramax behind every HD, the 6.0L Vortec in Savana and Sierra HD, the 4.3L V6 that has carried GMC light trucks for three decades, and the 3.6L LFX in Acadia, Terrain and Canyon. Our 1,973 verified GMC engines span all of it. Because GMC and Chevrolet share these engines outright, a unit pulled from a Silverado is frequently the correct part for a Sierra — which widens your options considerably, but makes the RPO code and generation the things that identify the part rather than the nameplate.

Every GMC engine we sell has been pulled from a low-mileage donor vehicle, cataloged by VIN, and held in our climate-controlled warehouse pending sale. Each unit goes through our six-step inspection — VIN-matching, ASE compression testing and leak-down evaluation, noise & smoke verification, full visual inspection, multi-angle photography, and palletized shipping. LS-family V8s get a specific AFM/DFM lifter inspection, since collapsed lifters are the documented weak point on those engines, and Duramax units get injector and emissions-hardware review. Rejected units never reach the buyer.

You pay a fraction of dealer-new pricing for identical GM engineering, ship free on a heavy-duty pallet anywhere in the continental U.S., and get 30 days from delivery to return for any reason — no restocking fees. The warranty printed on the listing — with extended coverage up to 3 years available — covers you if anything goes wrong after install. Across 100K+ engines and transmissions in stock, we hold a 0% fitment-related return rate.

📱 Fastest way to match: text us your VIN, get options in minutes.Text Your VIN →

Your GMC Engine Options: Compared

Most GMC owners face four real choices when the engine fails:

← Swipe sideways to see all columns →
Option Cost Reliability Warranty Fitment Match
Used OEM (this collection) $$$ Best Value High — tested Included VIN-matched
New OEM (dealer) $$$$$ 2-4× more High Manufacturer Exact
Aftermarket / Reman $$$$ Varies 6-12 mo May adapt
Junkyard $ Cheapest Unknown None DIY

Tested used OEM hits the sweet spot — same engineering as new, fraction of the cost.

GMC Engine Buying Guide

5 things to verify before buying a used GMC engine:

  1. Match on the RPO code, and treat Chevrolet donors as valid. GMC and Chevrolet share these engines outright — a unit from a Silverado is frequently the correct part for a Sierra. The RPO code on the glovebox or door-jamb label, plus the 8th digit of your VIN, identifies the exact unit GM built into your truck.
  2. 5.3L generations are not interchangeable. The 5.3L spans LM7, LMG, L83 and L84 across two decades, with different blocks, heads, injection systems and accessory drives. Displacement alone tells you almost nothing — match the generation.
  3. For LS-family V8s, verify AFM/DFM lifter status. Active Fuel Management and its successor Dynamic Fuel Management collapse lifters as a known failure mode. Ask whether AFM was deleted or if the lifters have been replaced — we inspect this on every LS-family unit before listing.
  4. For Duramax diesels, ask about injector and emissions history. LB7 injectors and LLY overheating are well documented; LMM and LML EGR and DPF systems are expensive if they were not maintained. Generation matters more here than on any other GMC engine.
  5. Confirm the match with your own VIN before you order. Your VIN settles the engine code, drivetrain and build split in one step. Text it to +1-307-441-5554 and we will confirm in writing exactly which unit fits your vehicle before you pay.

Our ASE-certified technicians verify every one of these points against your VIN before any unit ships.

📞 Need help choosing the right GMC engine? Talk to our team live.Call 1-877-313-8995

Frequently Asked Questions

What is the warranty on a used GMC engine?
Every GMC engine ships with a warranty included — the standard term follows the model year (1 month for 1990, 3 months for 1991–2000, 6 months for 2001 and newer) and is printed on each product page. Extended coverage of up to 3 years is available at checkout.
What does ASE-tested mean?
ASE-certified technicians compression-test every cylinder and run leak-down evaluation on engines; transmissions are Shift-Tested through all gears under load. Plus noise & smoke verification, visual inspection, and multi-angle photography before shipment.
How long until delivery?
Prep and ship time is 3-5 business days. Transit time is 2-3 business days after dispatch via freight carrier — typically 5-8 business days from order to delivery.
Can I see photos before I buy?
Yes. Multi-angle photos of the actual unit are sent before payment. If you do not approve the photos, you get every dollar back — no restocking fees, no return freight charges.
Do I need my VIN?
Strongly recommended for exact-fit matching. GMC engines vary by RPO code, generation and emissions calibration — a 5.3L has several non-interchangeable generations. Text your VIN to +1-307-441-5554 and we will match options in minutes.
How do I find my exact GMC engine?
Check the RPO code on the glovebox or door-jamb label, or send us the 8th digit of your VIN. GMC shares its engine catalog with Chevrolet, so a unit from a Silverado is frequently the correct part for a Sierra — the code is what matters, not the badge.
Why cheaper than dealer new?
Used OEM from low-mileage donor vehicles. Same GM engineering as factory new at a fraction of the cost — dealers are typically 2-4x our pricing, and many older units are no longer available new at all.
When can I reach customer service?
Call 1-877-313-8995 or text +1-307-441-5554 during the business hours shown in the site footer, or email info@autopowersource.com any time.
🏆 Earn $500 with Our Rewards Program
Every GMC engine you buy earns rewards. 10 orders (yours or referred) = $500 cash credit. Silver, Gold, and Platinum tiers with discounts, priority support, and private inventory access.
See How Rewards Work →
100K+
Engines+Transmissions In Stock
0%
fitment-related returns
All 50
states covered, free freight
36
brands covered

Our 6-Step Inspection & Shipping Process

Every GMC engine we ship has been through these six steps:

1. VIN-Matching
We match the donor VIN to your VIN to confirm engine code, generation, emissions calibration, and drivetrain fit.
2. Tested & Verified
ASE-certified technicians compression-test every cylinder and run leak-down evaluation on engines. Transmissions are Shift-Tested through all gears.
3. Noise & Smoke Verification
Units are run to verify normal mechanical sound and clean operation — catches internal wear static tests miss.
4. Visual Inspection
Every accessible component is inspected: turbos, manifolds, valve covers, AFM/DFM lifters, accessories, sensor harnesses.
5. Photograph & Catalog
Multi-angle photos sent to you BEFORE we ship for your approval.
6. Palletize & Ship
Strapped on a heavy-duty wooden pallet, shipped via freight at no charge.

Our Photos-Before-Shipment Guarantee

Before any engine leaves our warehouse, we send you multi-angle photographs. You approve. If you do not approve, you get every dollar back — no questions, no restocking fees, no return freight charges. On top of 30-day money-back and the warranty included with every unit. Browse all 1,973 GMC engines below.

✉ Email Us at info@autopowersource.com
No match? Text VIN →