Greetings, this is an F-284 mechanical (solid) lifter Crane camshaft from the late 1960's. It's a single pattern camshaft with 284 degrees advertised duration, and 241 degrees duration at .050" tappet lift. Lobe lift is .302", gross valve lift with 1.5:1 rocker arms is .453". Lobe separation is 112.5 degrees. Recommended valve lash at operating temperature is .028" intake, .032" exhaust. This should have a fair idle, with a basic rated RPM range from 2600 to 6000 RPM. Regards, Chase