NGK 6510 Iridium IX LTR7IX-11 Spark Plug Set (16) for 03-08 5.7L, 06-10 6.1L & 11-24 6.4L 392 HEMI
NGK Iridium IX plugs are built for performance engines. The 0.6mm fine-wire iridium center electrode lowers the voltage needed to fire, so your factory ignition makes a brighter, more consistent spark. The taper-cut ground electrode reduces quenching for better flame-kernel growth, sharper throttle response and strong anti-fouling resistance. Trivalent metal plating resists corrosion and seizing, and the copper core pulls heat out of the tip.
Fits
- 2003-2008 5.7L HEMI (non-VVT: Charger, Magnum, 300C, Grand Cherokee, Durango, RAM 1500)
- 2006-2010 6.1L SRT8 HEMI
- 2011-2024 6.4L 392 HEMI (Scat Pack, SRT 392, Grand Cherokee SRT, Durango SRT/R/T 392)
Specifications
- NGK stock number: 6510 / LTR7IX-11
- Heat range: 7
- Thread: 14mm
- Reach: 25mm
- Seat: Tapered
- Hex: 5/8"
- Gap: .044" (1.1mm)
- Center electrode: 0.6mm iridium fine wire
- Resistor: Yes
- Quantity: 16 plugs (complete HEMI set)
Why Iridium IX
- Lower firing voltage and a stronger spark from the stock coils
- Better throttle response, plus resistance to fouling on tuned and supercharged engines
- Corrugated ribs prevent flashover; triple seals prevent leakage
- Pure alumina silicate insulator for strength and heat transfer
FAQ
Why 16 plugs?
The HEMI fires two plugs per cylinder, so a V8 HEMI needs 16. This set does the whole engine.
My Challenger R/T is a 2009+ 5.7. Is this the right set?
No. The 2009+ 5.7L VVT HEMI uses the NGK 2309 LFR7AIX set. This 6510 set is for the 2003-2008 5.7L, the 6.1L and the 6.4L 392.
Do I need to gap them?
They come pre-gapped at .044". Check the gap before you install them, and don't pry on the fine iridium tip.
Questions about fitment or heat range for your build? Call 954-507-6261 or email sales@americanmuscleperformance.net.
