Aftermarket Sierra 18-5438 ignition coils with perfect application fitment Durable Construction,providing reliable performance and long service life Application specific design to ensure a perfect fit Fits GM V-6 & V-8 Engines With HEI Thunderbolt IV & V Ignition Replace part number Crusader 37068, R117004; Mercruiser 392-7803A4,392-805570A2,300-8M0079202; Marine Power 0805-100, Pleasurecraft Marine R117004, Mallory 9-29701 Aftermarket marine inboard ignition coil Compatible with MerCruiser Thunderbolt IV and V Ignition Systems with HEI - Replaces 18-5438, 392-805570A2, 392-7803A4, 392-805570A1, 72115, 40511