These cylinder kits come bored and honed to size and are ready to install. Supplied in sets for front and rear and complete with cast pistons, pins, retaining rings, moly faced piston ring sets and exhaust, head & base gaskets. With their stock bore of 3.500" they fit all Evolution Big Twin 1984 thru 1999 with stock stroke. Replacement pistons are supplied in sets for front and rear and include Moly faced ring sets, piston pins, and retaining rings. These can also be use in OEM and other aftermarket cylinders.