Requires special pushrod 418304HP alt 430121HP (4mm shorter)
All lifters have to be changed at the same time.
7 point inspection on lifters:
1. Parabolic crown specification
2. Concentricity 360 degree specification.
3. Correct grade "C" specification hardness.
4. Body diameter and taper.
5. Lifter assebly height.
6. Lifter crown surface finish.
7. External surfaces physically checked.