Edelbrock Rollin? Thunder Camshaft # 2268 is designed for 348/409 (W Series) engines from 1958-65 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 451HP and 470 Ft Lbs of Torque when paired with Performer RPM intake manifold # 7159, Performer Series Carbs # 1412, Performer RPM cylinder heads # 60815 and Edelbrock roller tappet lifter set # 97423. Must use a high stall torque converter. Camshaft specifications: ? Intake duration: 230 Degrees ? Exhaust duration: 234 Degrees ? Intake lift: .616? ? Exhaust lift: .628? ? Lobe separation: 112 Degree ? Intake Center Line: 107 ? Vacuum: 10?