AMS Racing Armor Coated King Brand SI-Series Connecting Rod Bearings for GM GEN III IV LS & Small Block Chevy Engines Fits -1997-2014 Gen 3/4 LS Based Engines with Stock Crankshafts 4.8L 5.3L 5.7L 6.0L 6.2L -Small Block Chevy 305 327 350 400 Engines Bearing Details King Bearings' bi-metal SI material blends Aluminum with 2.5-3% Silicon, providing strength. Ideal for medium-load engines, particularly engines using nodular cast iron crankshafts. It excels as a Lead-free OE replacement Bearing. AMS Armor Coating Details Our Armor Coating provides added protection against dry starts and oil starvation. By reducing bearing wear and flaking, we add an extra level of protection to the bearing. Due to the decreased friction, this also protects the bearings from heat build up.