wayne rhodes 5pts This engine for me, would have to have a hydraulic flat tappet cam and matching valve springs. Why? the roller combo is to hard on the valve train, the spring pressure on the roller rockers is way higher than a flat tappet hydraulic cam kit. If the roller rocker is not dead nuts on the center of the valve's it will beat one side of the valve stem flat causing the guide plate to wear on one side causing the roller to jump off the valve stem. the rocker maybe damaged and the valve & guide plate will need to be replaced. Having to remove the head. in the process. That is why getting the right length push rod is so critical, it can ruin your pocket book, and your day. All of the roller cam and components are much heaver than a simple hydraulic cam & kit. So replacing valve springs will be mandatory with the heavy roller set up.Don't get me wrong, at least 50 hp gain can be had with the roller set up.