This Comp Cams 23-630-5 BBM Drag Race Mechanical Flat Tappet Camshaft fits the 383-440 Big Block Chrysler from 1959-1980. Comp designed this cam for street/strip use, and it features excellent torque and a smooth idle. A 11.0:1 or higher compression ratio, 850+ CFM carb, 5.13 gear, and a 5400+ stall speed torque converter are highly recommended. Comp Cams 23-630-5 BBM Drag Race Mechanical Flat Tappet Camshaft Specs: For 383-440 cubic inch Big Block Chrysler engines from 1959-1980 Stock (O.E.) valve springs can NOT be used. Single Bolt Basic RPM Range: 5000 to 7200 Valve Lift Intake: .650 Valve Lift Exhaust: .650 Advertised Intake Duration: 324 Advertised Exhaust Duration: 324 Intake Duration at .050”: 290 Exhaust Duration at .050”: 290 Lobe Separation: 108 Firing Order: 1-8-4-3-6-5-7-2 Made in the USA Comp Cams designed this Mechanical Flat Tappet camshaft for high performance on the street and drag strip. Comp Cams –The Absolute Leader In Valve Train Technology!