These forged, 3-5/8" big bore flat topped pistons are used in S&S Sidewinder kits and Hot Set Up Kits for HD Evolution big twins with stock cylinder heads and 4-1/4" and 4-1/2" stroke engines with stock diameter (8-1/2") flywheels and 4-3/4" stroke engines with 8-1/4" diameter flywheels. 3-5/8" bore.
XMAS BREAK LAST SHIP DATE 18 DECEMBER
📦All new orders placed after that date will be shipped once we return on the 5th January 2026
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