Working with Manley Performance, Joe came up with a proprietary valve design that solves the problem. The trick valves feature the same overall length as stock Gen III Hemi valves (4.950-inch intake and 4.925-inch exhaust), but are machined with slightly lower valve lock grooves. This moves the retainer position down, away from the bottom of the rocker arm and opens the door for larger diameter straight-type valvesprings. The pen points to the end of the custom Superior/Manley valve. Also note the use of single groove locks, which give greater clamping force and eliminates the stem galling problem encountered with stock triple bead configuration seen on left.