The additional stresses of heavy duty and performance applications (such as increased bearing loads, increased RPMs, and increased horsepower) place a greater demand on the oil system, so if the oil pump isn't up to the job, premature engine failure is a very real possibility. Most heavy duty and performance applications require an increase in both volume and pressure, and Milodon "Hi-Volume/Hi-Pressure" oil pumps provide a 20 to 30 percent increase in both areas. Each pump is 100 percent flow tested to assure its proper operation, and backed by the manufacturer. Big Block Chevy high volume oil pump, for 396, 402, 427, 454 engines Fits all Milodon Big Block Chevy oil pans