Howards designed this cam for street/strip use, and it has a fair idle. A 9.5:1+ compression ratio and 2200+ stall speed torque converter are highly recommended. Howards Cams 110245-12 SBC Retro-Fit Hydraulic Roller Camshaft Specs. Basic RPM Range: 1800 to 5400. Valve springs can NOT be used.Howards Cams designed this Retro-Fit Hydraulic Roller Camshaft for high performance on the street and drag strip. Howards Roller Cams - From mild to wild, they are the ultimate in performance!