Std Flat Top Pistons with 9.0:1 Compression Ratio. Fits Sportster 1986-2021 with 1200cc Engine & Sportster 1986-1987 with 1100cc Engine. - Keith Black Pistons Indian Touring/Bagger The ILL-PRO-III also has left

The ILL-PRO-III also has left and right indicator light outputs for factory or custom turn signal indicator options

Direct replacement for OEM mirrors on models with 5/16″ mounting hole

* High traction knurled rubber design

* Handlebars with an emphasis on touring comfort

Std Flat Top Pistons with 9.0:1 Compression Ratio. Fits Sportster 1986-2021 with 1200cc Engine & Sportster 1986-1987 with 1100cc Engine. - Keith Black Pistons Indian Touring/Bagger The ILL-PRO-III also has left* Bore=3. 498 Stroke=3. 812 * Hypereutectic Alloy is a cast 16% silicon content material * Perfect for air cooled engines * Low thermal expansion rate = tighter piston to cylinder clearance Tech Tips: * 9. 0: 1 Compression Ratio with 69cc Head Chamber Volume. * Follow Ring End Gap & Piston to Cylinder Clearances as per the supplied Manufacturers Instructions. * Pull the engine down first & measure the existing bore to determine if oversize pistons are