Burris Flathead Piston Kit - Unplated - The Burris Flathead replacement piston kits are manufactured using the highest quality materials and on state of the art equipment. The high silicon alloy reduces expansion and reduces friction in the bore. Each kit comes complete with Burris rings, wrist pin* and clips. .040", .045" and .050" piston kits breathe new life into those older blocks.  AKRA, BNSS, IKF, KART & WKA approved for competition in all stock flathead classes. *The Burris wrist pin does not meet the currently published specifications for IKF and WKA. Check with your local track or series for legality as it has been accepted on the local and regional level in many instances.