When going through a head we replacement all hardware, including eccentrics.
Oversize eccentrics are often required to adjust the valves to spec when using a cam with a smaller base circle (typical on regrind cams). We like them better than lash caps. Specification: .028″ additional adjustment at the cam.
M10: order 8 eccentrics for full set.
M20/M30: order 12 eccentrics for full set.