Edelbrock's #97433 high performance hydraulic roller lifters for 1990 & earlier Big-Block Chevy Mark IV engines are the perfect match for street and high performance applications. With unsurpassed tolerance capable of high rpm power, these precision self-aligning retro-fit hydraulic roller lifters are designed for use in early model non-roller engine blocks originally equipped with conventional lifters. Sold in complete sets of 16.Installation Notes: • Allows the use of a modern roller camshaft in non-roller cam blocks • Lifters are made from 86L20 steel and the case is heat-treated to 50-52c hardness to a depth of .010" - .015" • Each lifter is tested and assembled to high quality standards • lifters are tied together for precision alignment • Tight ID tolerances allow for better control at higher RPM • Outside finish has a R.E.M. micro finish at 2 RMA • Lifters are designed for easy drop in replacement without block modifications • Highest quality lifters at a competitive price • Proper installation is the responsibility of the installer. Improper installation will void your warranty and may result in poor performance and engine or vehicle damage.