S&S 129" Big Bore kit for M8 107" engines




  • Black cylinders with silver highlights or all black 
  • 11.0:1 compression
  • Huge displacement increase means huge power increase
  • Works with stock crankcases & stock 4.375" stroke flywheels
  • Powder coat finish match factory finish, giving the bike a “sleeper” advantage
  • MLS (multi-layered steel) head gaskets
  • Retains stock engine height
  • Includes Cam Cover Badge
  • Made in the USA 

Payment & Security

Amazon American Express Apple Pay Diners Club Discover Meta Pay Google Pay Mastercard Shop Pay Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.

Estimate shipping