Chain drive. 487 CAM - The 487 Reaper CHOP is a great allround camshaft for 4-1/2 stroke 114" - 117" when looking for an aggressive bolt-in. The 487 has that nasty CHOP idle sound while producing a wide powerband that the Feuling cams are known for. Responds very well to increased bore and or compression; exhaust system and air cleaner. Use of performance valve-springs is not required but may result in a quieter; smoother running valve-train; like Feuling 993530 or 588021. Intake: .478 Valve Lift; 20.5 Open; 37 Close; 237 Duration @ 50"; .180 lift @ TDC; 98.5 Lobe Centerline. Exhaust: .487 Valve Lift; 44 Open; 17.5 Close; 241.5 Duration @ 50"; .146 lift @ TDC; 103.25 Lobe Centerline. Overlap: 38. *Cam specs measured in the engine on the lifter @ 0.050" using a 1.61 rocker arm ratio.