+.040in. Pistons with 8.5:1 Compression Ratio. Fits Big Twin 1941-1979 with 1200cc Engine. - Keith Black Pistons Speedo 4.5" Tank Mt 1936-03 * Twin Cam Style 4

* Twin Cam Style 4 Piston Caliper Upgrade

* Includes new rubber seal for a clean

* KRA-UN-ISO-9010 Isolatesd Riser Top Gauge Mount

Great low to mid RPM power

* Advised to add a small drop of blue loctite to headlight insert screws after assembly

+.040in. Pistons with 8.5:1 Compression Ratio. Fits Big Twin 1941-1979 with 1200cc Engine. - Keith Black Pistons Speedo 4.5" Tank Mt 1936-03 * Twin Cam Style 4Features & Benefits: * Bore = 3. 477 * Stroke = 3. 969 * Hypereutectic Alloy is a cast 16% silicon content material. * Perfect for air cooled engines. * Low thermal expansion rate = tighter piston to cylinder clearance. * Complete kit includes: two pistons, rings, wrist pins and clips. * Replaces OEM # 22146 55C * Replaces OEM # 22146 74A Tech Tips: * Follow Ring End Gap & Piston to Cylinder Clearances as per the supplied Manufacturers Instructions. *