Quick reference

Engine (2023 F-350)	OEM Plug PN	Aftermarket (NGK / Denso / Motorcraft / ACDelco)	Gap (in / mm)	Torque (lb-ft / Nm)	Interval
6.8L V8 Gas (pushrod)	Motorcraft – verify by VIN in Ford catalog (see notes)	Match by catalog: NGK/Denso/ACDelco equivalent to Ford OEM	See under-hood emissions label (varies by calibration); do not force-gap iridium	15 lb-ft / 20 Nm (verify in Ford WSM)	Typically 100,000 mi (160,000 km) with iridium
7.3L V8 Gas “Godzilla”	Motorcraft – verify by VIN in Ford catalog (see notes)	Match by catalog: NGK/Denso/ACDelco equivalent to Ford OEM	See under-hood emissions label (varies by calibration); do not force-gap iridium	15 lb-ft / 20 Nm (verify in Ford WSM)	Typically 100,000 mi (160,000 km) with iridium
6.7L Power Stroke Diesel	N/A (diesel—no spark plugs)	N/A	N/A	N/A	N/A

Notes:

Never guess spark plug part numbers—use your VIN in Ford’s parts catalog or a trusted aftermarket catalog to retrieve the exact Motorcraft plug and any approved cross-references. 2023 Super Duty calibration and emissions family can affect the specified plug and gap on the under-hood label.
Most 2023 gas F-350s ship with iridium fine-wire plugs from the factory.

Why the right plug matters

Heat range: Too hot a plug can cause pre-ignition; too cold can foul. Ford chooses a heat range to keep tip temperature self-cleaning without overheating. Stay with the specified heat range unless you have a documented tuning need.
Electrode metal:
- Iridium: Ultra-fine center electrode, best ignition performance and durability. Typical OE choice today; service life up to ~100k miles.
- Platinum: Good longevity and cost balance; usually 60k–100k miles depending on design and usage.
- Copper/nickel: Great conductivity but short life (~30k miles). Not typical OE on 2023 Super Duty.
Fitment details: Reach, thread, seat type, and projected tip geometry are critical. An incorrect reach can strike the piston or shroud the spark.

Check the under-hood emissions label or Ford service information for the specified gap for your exact calibration.
Use a wire-style gap gauge (not a coin/wedge) to measure. Slide the correct wire through the gap; it should drag lightly.
If adjustment is needed on non-iridium or robust fine-wire plugs, bend only the ground strap—never pry on the center electrode. Use a gapping tool with a dedicated tang to nudge the strap.
Re-check after any adjustment. Keep the center electrode perfectly centered under the ground strap.
Many modern iridium plugs are pre-gapped and fragile at the tip. If the measured gap is out of spec out of the box, exchange the plug rather than bending the strap aggressively.

Configuration: Both gas engines use coil-on-plug (COP). There is no distributor.
Access: Remove the engine cover and intake ducting as needed. On Super Duty trucks there’s generous room, but a small swivel and 5/8" spark plug socket help for rear cylinders.
Debris control: Blow out plug wells with compressed air before removing plugs to prevent dirt from entering the cylinder.
Removal: Work on a cool engine. Crack each plug loose, then back out by hand. If a plug feels stuck, apply a small amount of penetrating oil to the shell threads and allow time; work it gently to avoid thread damage.
Anti-seize: Ford/Motorcraft specify no anti-seize on plated spark plug threads. Anti-seize can alter torque and lead to over-tightening. If a prior technician used anti-seize, reduce torque by ~20–30%—but the preferred practice is clean, dry threads.
Installation torque: Thread new plugs in by hand to avoid cross-threading. Torque to 15 lb-ft (20 Nm) unless your Ford workshop manual/emissions label specifies otherwise for your exact engine build.
Coils and boots: Inspect COP boots for oil or carbon tracking; replace any compromised boots. Apply a thin film of dielectric grease inside each boot to ease future service and help seal out moisture. Reinstall coil hold-down bolts snugly (check Ford WSM; many COP bolts are in the 7–9 Nm range).
Battery and KAM: After service, a brief idle relearn may occur as the PCM trims fuel; a short drive cycle will stabilize it.

Ford 3-valve two-piece plug breakage (2004–2008 4.6/5.4/6.8 Triton): Not applicable to 2023 F-350 6.8L/7.3L pushrod V8s. Those legacy issues involved long-reach two-piece plugs; your 2023 engines use modern one-piece designs.
Broken porcelain during removal: Rare on low-mileage 2023 trucks; usually caused by removing plugs from a hot head or by side-loading the plug with the socket. Always let the engine cool and use a proper spark plug socket.
GM ionization-sensing coils: Not applicable to Ford.

To avoid errors, source plug part numbers by VIN from:

Using the exact OE-referenced plug ensures correct heat range, reach, and tip design for your 2023 calibration.

Need plugs replaced? Find a shop on Repairius.

Values can vary by engine, trim and build date; check your VIN-specific service information. Updated 2026-10-13.