+.030in. Dome Top Pistons with 8.2:1 Compression Ratio. Fits Sportster 1972-1985 with 1000cc Engine. - Keith Black Pistons RR Shocks Related - Softail tumbler on the road with

tumbler on the road with you

* Upgrade on OEM # 37813-06 & 37816-11

* As of 23/01/2008 this product has been upgraded to fit Dyna 2006up

* Does not fit Throttle By Wire Models

as well as the traditional method of pulling air from the sides

+.030in. Dome Top Pistons with 8.2:1 Compression Ratio. Fits Sportster 1972-1985 with 1000cc Engine. - Keith Black Pistons RR Shocks Related - Softail tumbler on the road withFeatures & Benefits: * Bore = 3. 218 * Stroke = 3. 812 * Fits Iron Head Sporty. * 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 # 22255 83 Tech Tips: * 8. 2: 1 Compression Ratio with 110cc Head Chamber Volume. * Follow Ring End Gap & Piston to Cylinder