1965 - 1996 Chevrolet 396-502 (Mark IV) Hydraulic Roller 3400 to 6700 Camshaft All Howards Cams use the highest-grade race quality cores available. All hydraulic and mechanical flat tappet camshafts are 100% Rockwell checked and Parkerized to ensure the highest quality control standards available anywhere. Howards Cams are manufactured on dedicated high precision CNC cam grinding machines. Most Howards Cams are packaged and shipped in our unique, hard, high impact plastic reusable cases. This ensures that the high quality camshaft that went into the case comes out in the same condition, when delivered, as when it was packed. Lift: .640 / .640, Duration @ .050: 249 / 249, Centerline: 106, Rough idle, Hot street/bracket, Needs 10.5:1+ compression, 3500+ stall converter, headers & good intake.