Std Dome Top Pistons with 8.3:1 Compression Ratio. Fits Big Twin 1978-1984 with 1340cc Shovel Engine. - Keith Black Pistons Brake Pads * Spring-loaded ball plunges down

* Spring-loaded ball plunges down on the seat securing any leak in the Off Position

Stainless Steel on Head Gaskets & Copper on Exhaust Gaskets

* Polished Caliper

STD = KB Piston Kit

Std Dome Top Pistons with 8.3:1 Compression Ratio. Fits Big Twin 1978-1984 with 1340cc Shovel Engine. - Keith Black Pistons Brake Pads * Spring-loaded ball plunges downFeatures & Benefits: * Bore = 3. 498 * Stroke = 4. 250 * 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 # 21990 80 Tech Tips: * 8. 3: 1 Compression Ratio with 117cc Head Chamber Volume. * Follow Ring End Gap & Piston to Cylinder Clearances as per the