Broken rocker arms two weekends in a row

I've checked all the clearances, nothing is binding or hitting, no evidence of any valve to piston contact.
Retainer to guide? I'm sorry. I'm not like the others. I refuse to believe they are breaking "just because" they're aluminum. Harland Sharp makes some of the best rockers in the world. I believe you have something wrong somewhere. Well not "you" but you understand what I'm saying.