Edelbrock Rollin? Thunder Camshaft # 2261 is designed for 396-502 V8 Mark IV and Gen V engines from 1967-95 and produce optimum torque from the low-end to the mid-range. Rollin? Thunder camshafts match with Performer manifolds for vehicles operating from off-idle to 5500 rpm. They are smooth idling cams for daily drivers, trucks, vans, RVs and 4x4s. You can expect a major improvement in throttle response and torque. In the manifold section you'll find torque graphs showing the power gains from Performer manifolds and Performer-Plus cams. All camshafts include flat tappet lifters (except for cams designed for use with stock roller lifters), assembly lube and instructions. This cam produced 611HP and 573 Ft Lbs of Torque when paired with Victor Jr. intake manifold # 2902 and Victor Jr. 24 Degree cylinder heads # 77485 on a GM ZZ-502 short block. Not for 1965-66 Big Block Chevy?s running a grooved rear cam journal. Use with a high stall torque converter and stock ratio rocker arms only. Camshaft specifications: ? Intake duration: 236 Degrees ? Exhaust duration: 245 Degrees ? Intake lift: .625? ? Exhaust lift: .639? ? Lobe separation: 112 Degree ? Intake Center Line: 109 Degree ? Vacuum: 10?