Rocker studs snaping

There was an article a couple years ago about building a Magnum based engine with EQ heads. That article mentioned changing to a different rocker arm because they found binding, which sounds the same as this situation. You will need a set of adjustable guide plates to center the rollers properly over the valve tips (front to rear) but that won’t fix the breakage. You already showed the witness marks on the rocker arm as RustyRatRod suggested.
I have the same Edelbrock heads and I am ordering adjustable guide plates too, since mine have poor alignment as well. But rocker arms have no witness marks like yours.
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