Adjustable rockers are a must to achieve proper lifter preload (hydraulic) or valve lash (solid). We moved up to 1.6-ratio rockers from Indy. This meant the .501-lift Comp Cams stick would have .531 lift at the valve with the 1.6 rockers. The 1.6-ratio rockers will also aid the air velocity going through the larger-than-stock ports. Out of focus are the external oil lines at the rear of the heads.