Holroyd BBC Rocker Arms

[Mike Taylor 3601]

with weaker springs most time breakage comes from valve float or bounce which beats valvetrain to death most of the time when you have float the keeper grooves will be burred
and have to dress them down to get valve through guide and valve seat will be wider where valve has hammered it.
I believe alot of rocker breakage with higher spring pressure is from flex,they get wiggled to death. Which I say Clark's rocker reduces.
You break studs or pull threads out of head most likely there is valve float.
You may agree or disagree but stocker valve train have been push to edge and over whether in spring pressure/duration,overlap checked rules or current rules,and no matter what the rules are they will still be on the edge,because most everyone is going for all they can get.
Mike Taylor 3601