This Howards Cams 190325-12 Hydraulic Roller Camshaft fits the Gen III/IV LS engines from 1997 through Present. Howards designed this cam specifically for Rectangular Port Cylinder Heads on aggressive street/strip applications, and it features mid-torque & horsepower. A 11.0:1+ compression ratio, good heads, and a 2400+ stall speed torque converter are highly recommended. Howards Cams 190325-12 Gen III/IV LS Hydraulic Roller Camshaft Specs. For Gen III/IV LS engines from 1997 through Present.For use with Rectangular Port Cylinder Heads. Basic RPM Range: 2000 to 7200. Valve springs can NOT be used. Howards Cams designed this hydraulic roller camshaft for high performance on the street and at the drag strip. Howards Roller Cams - From mild to wild, they are the ultimate in performance!