Flathead Power® Forged 3-5/8" Bore Stroker Pistons replace several cast and forged big bore pistons that S&S® previously offered. Applications for this piston include 88", 4-1/4" stroke, 93", 4-1/2" stroke, and 96", 4-5/8" stroke, engines with stock 8-1/2" diameter flywheels and 98", 4-3/4" stroke, and 103", 5" stroke, engines with 8-1/4" small diameter flywheels. As with the new stock bore stroker piston, the modern metallurgy and advanced skirt profiles allow a relatively close piston fit for low engine noise and long engine life.