Keith Black pistons have several important advantages over conventional alloy pistons. KB Hypereutectic Pistons high silicon content yields superior thermal and wear characteristics, greater strength, scuff and seizure protection, and resistance to cracking. High silicon content also keeps heat in the combustion chambers, eliminating heat transfer and improving combustion. Sold in sets of eight with wrist pins (except Ford 2300cc, sold in sets of four). Claimer Performance Piston Series achieve maximum performance with high piston ring placement and low thermal conductivity. Top rings operate at higher temps and require slightly larger end gaps (4.000" bore x .0065" gap factor = .026" total end gap). It is recommended that ignition timing be retarded 2-4A. Sold in sets of eight with wrist pins. United Engine and Machine Company was started in 1922 in Fresno, California. The company relocated to Carson City, Nevada in 1978, where it has continued to grow. Since it's move, United Engine has continued to look at it's role in the domestic and world market. Currently, UEM manufactures the Silv-O-Lite OE aftermarket piston line, KB Performance Pistons (including the motorcycle division), and The Claimer Performance Piston Series. United Engine and Machine Company is now enjoying more than 80 years in business. The name Silv-O-Lite originated from the fact that small amounts of silver were alloyed into the aluminum. Hence the name. This name goes back to the companys's earliest beginning in 1922. We feature KB Performance Pistons, Silv-O-Lite Pistons and The Claimer Performance Series Pistons at low everyday prices!