M8 139″ Pro Street 4×2
Featuring our Big Cubic inch, big power touring package. The 139” motor comes standard with our custom lined cylinders that feature longer bezels to keep piston rock down and keep the piston much more stable in the cylinder. The Pro Street 4×2 head is fully CNC ported with all new intake and exhaust seats, new guides, +4mm intake valves , +2mm exhaust valves and our Premium High Lift Springs. Pair this kit with one of our performance touring cams and see huge torque and horsepower that jumps right up and carries all the way through the RPM’s. This kit is perfect for the customer looking for big cubic inch power on a motor that can still be a legitimate pump gas touring bike.
This build does require a full bottom end service. Below you will find a spec sheet for the top end only and one for the top and bottom end service. If you would like more information on our M8 Bottom End Service, click here.