Bosch Platinum Hi-Po 383 - 400 - 440 Spark Plugs Set of eight (8) in OEM factory packages A set of 8 spark plugs for all hi-po 383, 413, 426W, and 440 big-block Mopars. In unopened factory packages.  These are the famous German-made Bosch Platinum plugs, favored by Chrysler Engineers, in the hard-to-find 3/8" reach big-block size (WR9FP). Super-wide heat range, replacing J9Y, J10Y, J11Y and J12Y. This feature: > Prevents detonation and knocking...> Can actually prevent melted pistons!> Drastically reduces "loading up" and misfiring> Extended plug life> Improves idle and HP output - no misfires! Add S&H per calculator at tab above -- several choices -- shipped worldwide. MoPar to ya! Rick Partial list of models and years it fits: Road Runner Barracuda Plymouth Dodge Chrysler Hemi Coronet Challenger Duster Swinger Fury Polara Monaco Newport New Yorker Belvedere Satellite Dart 300 'Cuda 413 383 400 440 361 426W Charger Super Bee Valiant GTX R/T 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 Layout, HTML, text & photos © 2000 - 2025 R. Ehrenberg, all rights reserved