The intake roof has been raised for enhanced airflow. Intake runner volume is 200cc, chamber volume is 64cc. The heads have an extra thick deck, hardened intake and exhaust seats with manganese bronze valve guides. Heads are complete with +.100" 2.020" OR 2.055" stainless steel intake and 1.60" stainless steel exhaust valves, chromoly retainers, 10degree locks, screw in studs and guide plates assembled with 120lbs@1.800 single valve springs with dampers. This combination will allow up to a .600" lift camshaft.