2023 Used GMC Engines For Sale

18
verified 2023 GMC engines
Trustpilot
Customer Reviews
Up to 3 yrs
extended warranty available
Photos before
shipment

2023 Used GMC Engines For Sale

18 verified used 2023 GMC engines in stock, every one matched by RPO option code and the 8th VIN digit before it ships — the 6.6L L8T gas big block and the 6.6L L5P Duramax across the Sierra HD range, the 5.3L L84 EcoTec3 V8 in Sierra 1500, the 4.3L LV1 in the Savana vans, and both Acadia fours and sixes. Free freight, photos before we ship, 30 days to return.

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

2023 GMC Engine Families

Which engine sits under which 2023 GMC, and how many of each we hold today.

Engine family Fits (2023) In stock
6.6L L8T Big-Block V8 (Gas) Sierra 2500 HD / 3500 HD and Savana 2500 / 3500, Denali included — VIN 7, the 401-hp gas big block 6
6.6L L5P Duramax Turbo-Diesel V8 Sierra 2500 HD / 3500 HD, Denali included — VIN Y, 445 hp and 910 lb-ft 3
3.6L LGX V6 Acadia — VIN S, listed with and without the Opt V08 heavy-duty cooling package 2
4.3L LV1 EcoTec3 V6 Savana 2500 and 3500 — VIN P, the last pushrod V6 in the vans 2
5.3L L84 EcoTec3 V8 Sierra 1500 and Sierra Denali 1500 — VIN D, Dynamic Fuel Management 2
2.0L LSY Turbo I4 Acadia — VIN 4, the turbocharged four 1
2.7L L3B TurboMax I4 Sierra 1500 — VIN K, the turbocharged four 1
3.0L LZ0 Duramax Turbo-Diesel I6 Sierra Denali 1500 — VIN 8, second-generation 3.0 inline-six 1
Total 18

Other GMC Model Years

Every model year we hold GMC engines for. Years without a link are in stock but have no year page yet — text us your VIN.

20242023
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990

Why Buy a 2023 GMC Engine from Auto Power Source

On a 2023 GMC the displacement on the badge settles almost nothing. Two completely different 6.6L V8s sit in the Sierra 2500 HD and 3500 HD: the L8T is a gasoline big block rated 401 hp, the L5P is the Duramax turbo-diesel rated 445 hp and 910 lb-ft. They share no block, no heads, no fuel system and no mounting. The RPO option code on the service parts identification label, and the 8th digit of the VIN, are what separate them — and six of the eighteen units on this page are L8T while three are L5P.

The light-duty side splits the same way. Sierra 1500 ships with the 2.7L L3B TurboMax four (VIN K), the 5.3L L84 EcoTec3 V8 (VIN D) and, on Denali, the 3.0L LZ0 Duramax inline-six (VIN 8) — the second-generation 3.0, not the earlier LM2. The Savana 2500 and 3500 vans keep the 4.3L LV1 pushrod V6 alongside the 6.6L L8T. The Acadia is listed two ways again: the 2.0L LSY turbo four (VIN 4) and the 3.6L LGX V6 (VIN S), and the LGX appears both with and without the Opt V08 heavy-duty cooling package, which changes the radiator and fan assembly rather than the engine itself.

Denali is a trim, not a drivetrain — a Sierra Denali 1500 takes the same L84 as an SLE, and a Sierra Denali 3500 takes the same L8T or L5P as the base 3500 HD, so we list them under their base nameplate and let the option code decide. Every unit here is used OEM pulled from a low-mileage donor vehicle, cataloged against its VIN, compression-tested and leak-down evaluated by ASE-certified technicians, photographed for your approval, and shipped free on a pallet with 30 days to return it.

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

Your 2023 GMC Engine Options: Compared

Most 2023 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.

2023 GMC Engine Buying Guide

5 things to verify before buying a used 2023 GMC engine:

  1. Settle which 6.6L you need before anything else. The L8T is the gasoline big-block V8 (VIN 7); the L5P is the Duramax turbo-diesel (VIN Y). Both read “6.6L” on a 2023 Sierra 2500 HD or 3500 HD and on the Savana. They share no parts and no mounting.
  2. The 3.0L in a 2023 Sierra is the LZ0, not the LM2. GM updated the 3.0 Duramax inline-six for 2023 — VIN 8, Opt LZ0. Same displacement and layout as the earlier LM2, separate part numbers. Confirm the code before you buy a 3.0.
  3. Read the RPO code, not just the displacement. GMC identifies 2023 hardware by option code — L8T, L5P, L84, LV1, LGX, LSY, L3B, LZ0. The code appears on the service parts identification label in the glovebox and is the fastest way to confirm what came out of your vehicle.
  4. On an Acadia 3.6L, check the cooling package. The 3.6L LGX is listed both with Opt V08 heavy-duty cooling and without it. The engine is the same; the radiator, fan and shroud assembly are not, so the package affects what has to come across with the unit.
  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 2023 GMC engine? Talk to our team live.Call 1-877-313-8995

Frequently Asked Questions

What is the warranty on a used 2023 GMC engine?
Every 2023 GMC engine ships with a warranty included, 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 a leak-down evaluation, then noise and smoke verification, a full visual inspection, and multi-angle photography before shipment.
How long until delivery?
Prep and ship is 3-5 business days, transit 2-3 business days after dispatch by freight carrier.
Can I see photos before I buy?
Yes. Multi-angle photos of the actual unit are sent before payment. If you do not approve them, you get every dollar back.
Do I need my VIN?
Yes. On a 2023 GMC the 8th digit separates the 6.6L L8T gas V8 from the 6.6L L5P Duramax, and the 2.0L LSY from the 3.6L LGX in the Acadia. Text your VIN to +1-307-441-5554.
Which 2023 GMC models do you stock?
Sierra 1500, Sierra 2500 HD and 3500 HD including Denali, Savana 2500 and 3500, and Acadia.
Why cheaper than dealer new?
Used OEM from low-mileage donor vehicles — the same GM engineering and the same RPO-coded hardware, at a fraction of a new crate price.
When can I reach customer service?
Call 1-877-313-8995 or text +1-307-441-5554 during the hours in the site footer, or email info@autopowersource.com.
🏆 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 2023 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 18 2023 GMC engines below.

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