# NGK Iridium IX Spark Plug Box of 4 (YR55IX) NGK Iridium IX spark plugs are specifically designed for the performance enthusiast. Iridium IX provides outstanding acceleration, high fuel efficiency and durability. NGK Iridium IX plugs offer extreme ignitability and exceptional anti-fouling. Tapered cut ground electrode provides improved starting, idling and throttle response. The Iridium fine wire center electrode's durability is six times harder than platinum. Iridium alloy's extremely high melting point is perfect for today's engines. For even greater performance consider upgrading to an NGK Ruthenium HX plug. - RECOMMENDED USAGE: Modified or high performance applications, or as an upgrade to OE nickel alloy spark plugs - Trivalent metal plating for superior anti-corrosion and anti-seizing properties - Outstanding acceleration, high fuel efficiency and durability - Fine iridium tip ensures durable and consistent spark This Part Fits: Year Make Model Submodel 1975 Buick Apollo Base 1975 Buick Apollo SR 1975 Chevrolet Bel Air Base 1978 Chevrolet C10 Big Ten 1975,1977-1978 Chevrolet C10 Cheyenne 1975,1977-1978 Chevrolet C10 Custom Deluxe 1975,1977-1978 Chevrolet C10 Scottsdale 1975,1977-1978 Chevrolet C10 Silverado 1975,1977-1978 Chevrolet C10 Suburban Custom Deluxe 1975,1977-1978 Chevrolet C10 Suburban Scottsdale 1975,1977-1978 Chevrolet C10 Suburban Silverado 1975,1977-1978 Chevrolet C20 Cheyenne 1975,1977-1978 Chevrolet C20 Custom Deluxe 1975,1977-1978 Chevrolet C20 Scottsdale 1975,1977-1978 Chevrolet C20 Silverado 1975,1977-1978 Chevrolet C20 Suburban Custom Deluxe 1975,1977-1978 Chevrolet C20 Suburban Scottsdale 1975,1977 Chevrolet C20 Suburban Silverado 1975,1977-1978 Chevrolet C30 Cheyenne 1975,1977-1978 Chevrolet C30 Custom Deluxe 1975,1977-1978 Chevrolet C30 Scottsdale 1975,1977-1978 Chevrolet C30 Silverado 1975 Chevrolet Camaro Base 1975 Chevrolet Camaro LT 1975 Chevrolet Camaro RS 1975 Chevrolet Caprice Classic 1975 Chevrolet Caprice Classic Sport 1975 Chevrolet Caprice Estate Wagon 1975 Chevrolet Chevelle Laguna Type S-3 1975 Chevrolet Chevelle Malibu 1975 Chevrolet Chevelle Malibu Classic 1975 Chevrolet Chevelle Malibu Classic Estate 1975 Chevrolet Corvette Stingray 1975,1978 Chevrolet El Camino Base 1975 Chevrolet El Camino Classic 1978 Chevrolet El Camino Conquista 1975,1978 Chevrolet El Camino SS 1975-1978 Chevrolet G10 Beauville 1975-1978 Chevrolet G10 Chevy Van 1975-1978 Chevrolet G10 Sportvan 1974 Chevrolet G10 Van Base 1974 Chevrolet G10 Van Sportvan 1975-1978 Chevrolet G20 Beauville 1975-1978 Chevrolet G20 Chevy Van 1978 Chevrolet G20 Nomad 1975-1978 Chevrolet G20 Sportvan 1974 Chevrolet G20 Van Base 1974 Chevrolet G20 Van Sportvan 1975-1978 Chevrolet G30 Beauville 1975-1978 Chevrolet G30 Chevy Van 1975-1978 Chevrolet G30 Hi-Cube 1975-1978 Chevrolet G30 Sportvan 1974 Chevrolet G30 Van Base 1974 Chevrolet G30 Van Sportvan 1975 Chevrolet Impala Base 1975 Chevrolet Impala Custom 1975 Chevrolet Impala Sport 1975,1977-1978 Chevrolet K10 Cheyenne 1975,1977-1978 Chevrolet K10 Custom Deluxe 1975,1977-1978 Chevrolet K10 Scottsdale 1975,1977-1978 Chevrolet K10 Silverado 1975,1977-1978 Chevrolet K10 Suburban Custom Deluxe 1975,1977-1978 Chevrolet K10 Suburban Scottsdale 1975,1977 Chevrolet K10 Suburban Silverado 1975,1977-1978 Chevrolet K20 Cheyenne 1975,1977-1978 Chevrolet K20 Custom Deluxe 1975,1977-1978 Chevrolet K20 Scottsdale 1975,1977-1978 Chevrolet K20 Silverado 1975,1977-1978 Chevrolet K20 Suburban Custom Deluxe 1975,1977-1978 Chevrolet K20 Suburban Scottsdale 1975,1977 Chevrolet K20 Suburban Silverado 1977-1978 Chevrolet K30 Cheyenne 1977-1978 Chevrolet K30 Custom Deluxe 1977-1978 Chevrolet K30 Scottsdale 1977-1978 Chevrolet K30 Silverado 1975,1977-1978 Chevrolet K5 Blazer Cheyenne 1975,1977-1978 Chevrolet K5 Blazer Custom Deluxe 1978 Chevrolet K5 Blazer Silverado 1975 Chevrolet Monte Carlo S 1975 Chevrolet Monza 2+2 1975 Chevrolet Monza S 1975 Chevrolet Nova Base 1975 Chevrolet Nova Custom 1975 Chevrolet Nova LN 1975 Chevrolet Nova Police 1975,1977 Chevrolet P10 Base 1975,1977 Chevrolet P10 Step-Van 1975,1977-1978 Chevrolet P20 Base 1975,1977-1978 Chevrolet P20 Step-Van 1975,1977-1978 Chevrolet P30 Base 1975,1977-1978 Chevrolet P30 Step-Van 1975,1977-1978 GMC C15 Base 1977-1978 GMC C15 Heavy Half 1975,1977-1978 GMC C15 High Sierra 1977 GMC C15 Indy Hauler 1975,1977-1978 GMC C15 Sierra Classic 1975,1977-1978 GMC C15 Sierra Grande 1978 GMC C15 Street Coupe 1975,1977-1978 GMC C15 Suburban Base 1975,1977-1978 GMC C15 Suburban High Sierra 1975,1977-1978 GMC C15 Suburban Sierra Classic 1975,1977-1978 GMC C15 Suburban Sierra Grande 1975,1977-1978 GMC C25 Base 1975,1977-1978 GMC C25 High Sierra 1975,1977-1978 GMC C25 Sierra Classic 1975,1977-1978 GMC C25 Sierra Grande 1975,1977-1978 GMC C25 Suburban Base 1975,1977-1978 GMC C25 Suburban High Sierra 1975,1977-1978 GMC C25 Suburban Sierra Classic 1975,1977-1978 GMC C25 Suburban Sierra Grande 1975,1977-1978 GMC C35 Base 1975,1977-1978 GMC C35 High Sierra 1975,1977-1978 GMC C35 Sierra Classic 1975,1977-1978 GMC C35 Sierra Grande 1978 GMC Caballero Base 1978 GMC Caballero Diablo 1978 GMC Caballero Laredo 1975,1977-1978 GMC G15 Rally 1975,1977-1978 GMC G15 Rally STX 1975,1977-1978 GMC G15 Vandura 1974 GMC G15/G1500 Van Rally 1974 GMC G15/G1500 Van Vandura 1975,1977-1978 GMC G25 Rally 1975,1977-1978 GMC G25 Rally STX 1975,1977-1978 GMC G25 Vandura 1974 GMC G25/G2500 Van Rally 1974 GMC G25/G2500 Van Vandura 1975,1977-1978 GMC G35 Magnavan 1977-1978 GMC G35 Rally 1977-1978 GMC G35 Rally Camper Special 1977-1978 GMC G35 Rally STX 1977-1978 GMC G35 Vandura 1977-1978 GMC G35 Vandura Special 1974 GMC G35/G3500 Van Base 1974 GMC G35/G3500 Van Rally 1974 GMC G35/G3500 Van Vandura 1975,1977-1978 GMC Jimmy Base 1975,1977-1978 GMC Jimmy High Sierra 1975,1977-1978 GMC Jimmy Sierra Classic 1975,1977-1978 GMC Jimmy Sierra Grande 1978 GMC Jimmy Street Coupe 1975,1977-1978 GMC K15 Base 1975,1977-1978 GMC K15 High Sierra 1977 GMC K15 Indy Hauler 1975,1977-1978 GMC K15 Sierra Classic 1975,1977-1978 GMC K15 Sierra Grande 1975,1977 GMC K15 Suburban Base 1975,1977 GMC K15 Suburban High Sierra 1975,1977 GMC K15 Suburban Sierra Classic 1975,1977 GMC K15 Suburban Sierra Grande 1975,1977-1978 GMC K25 Base 1975,1977-1978 GMC K25 High Sierra 1975,1977-1978 GMC K25 Sierra Classic 1975,1977-1978 GMC K25 Sierra Grande 1975,1977-1978 GMC K25 Suburban Base 1975,1977-1978 GMC K25 Suburban High Sierra 1975,1977-1978 GMC K25 Suburban Sierra Classic 1975,1977-1978 GMC K25 Suburban Sierra Grande 1977-1978 GMC K35 Base 1977-1978 GMC K35 High Sierra 1977-1978 GMC K35 Sierra Classic 1977-1978 GMC K35 Sierra Grande 1975 GMC P15 Base 1975 GMC P15 Value Van 1975,1977-1978 GMC P25 Base 1975,1977-1978 GMC P25 Value Van 1975,1977-1978 GMC P35 Base 1975,1977-1978 GMC P35 Value Van 1975-1977 GMC Sprint Base 1975-1977 GMC Sprint Classic 1975 GMC Sprint High Sierra 1976 GMC Sprint Sierra Madre Del Sur 1975-1976 GMC Sprint SP 1975 Oldsmobile Cutlass Base 1975 Oldsmobile Cutlass S 1975 Oldsmobile Cutlass Supreme Base 1975 Oldsmobile Omega Base 1975 Oldsmobile Omega Salon 1975 Pontiac Firebird Base 1975 Pontiac Firebird Esprit 1975 Pontiac Grand LeMans Base 1975 Pontiac LeMans Base 1975 Pontiac LeMans Sport 1975 Pontiac Ventura Base 1975 Pontiac Ventura Custom 1975 Pontiac Ventura S 1975 Pontiac Ventura SJ ## Details - **Price:** 74.61 CAD - **Vendor:** NGK - **Type:** Spark Plugs ## Variants | Variant | Price | Available | |---------|-------|-----------| | Default Title | 74.61 CAD | In stock | ## Images - Photo - Primary - Photo - Primary - Photo - out of package - Photo - out of package --- > Source: [Standard Auto Part](https://www.standardautopart.com/products/ngk-iridium-ix-spark-plug-box-of-4-yr55ix) > Updated: 2026-06-27