NGK Iridium IX TR5IX Spark Plugs for C5 Corvette LS1
NGK Iridium IX TR5IX spark plugs, stock number 7397, fit the 1997–2004 C5 Corvette with the LS1 5.7L engine. This offer includes eight spark plugs supplied as two packs of four.
A C5 plug service is a chance to give all eight LS1 cylinders the same replacement plug design. The fine iridium firing tip supports a stable spark and resists electrode wear, while the plated shell helps protect the threads during service. Whether you drive your Corvette regularly or bring it out for weekend trips, this set keeps the full V8 plug quantity together in one order.
Product Details
- NGK stock number: 7397; design code: TR5IX.
- Fine-wire iridium center electrode: A durable firing tip designed to maintain a consistent spark.
- Eight spark plugs: Two manufacturer packs of four, enough for one V8.
- Spark plugs only: Plug wires and ignition coils are separate components and are not included.
- Trivalent shell plating: Helps resist corrosion and supports removal at a later plug service.
Benefits
- One complete plug order: Replace all eight plugs with a matching Iridium IX design.
- Durable firing tip: Iridium resists electrode wear while supporting stable ignition.
- Service-friendly protection: Plated shells help protect the threads when your LS1 is due for its next plug change.
Important Notes
- Body-style coverage: LS1 coupe fitment runs from 1997–2004, convertible fitment from 1998–2004, and Fixed Roof Coupe fitment from 1999–2000. Match your own car’s year and engine before ordering.
- For an engine-swapped C5: Have your installer confirm the plug requirements for the engine actually fitted. The original body style alone does not establish the correct plug selection.
- Check before fitting: Confirm TR5IX and 7397 on the plugs and packaging, then inspect the ceramic insulators and electrodes for damage.
- Installation gap: Use 0.040 inch for this stock LS1 fitment. Measure every plug before installation; the supplied gap is not a substitute for the vehicle’s required setting.
- Protect the fine tip: Use a round-wire or pin gauge. Any adjustment must move only the ground electrode without levering against the center tip. Ask a qualified installer if a large adjustment is needed.
- Dry threads and correct torque: Do not add anti-seize or lubricant. Follow the vehicle’s tightening specification so the plug seats correctly and transfers heat as intended.
CORVETTE COMPATIBILITY
- 1997–2004 C5 Corvette LS1 coupe
- 1998–2004 C5 Corvette LS1 convertible
- 1999–2000 C5 Corvette LS1 Fixed Roof Coupe
- LS1 5.7L engine, stock configuration
- Manual and automatic transmissions
Why Buy from Custom Corvette Accessories?
At Custom Corvette Accessories, we’re Corvette owners ourselves, and we offer one-on-one customer service to help you choose parts for your car. Have a question about NGK 7397 TR5IX Iridium IX spark plugs for your C5 Corvette LS1? Contact us for personal help before you order.
✅ In-stock items ship in 1–2 business days via Standard Ground.
✅ Free shipping items are available in the Continental US only.
✅ Custom quotes available for 2-Day, Next Day, or Saturday delivery.
✅ Custom or backordered items ship as soon as available.
