Broken rocker arms two weekends in a row

Les Gibson said

Asking if anyone might have any thoughts on what might be causing this.
For consecutive weeks I've broken an exhaust rocker arm. Last week #4 exhaust rocker broke. This past Friday night #5 exhaust rocker broke. These are Harland Sharp rockers installed on Mopar Performance aluminum W5 heads. There's no oiling issue or clearance issues. I am told by the previous owner of my Arrow that these rockers are about 6 years old. Is this a case that they're just wore out and I need a new set or is there another reason. Appreciate any constructive thoughts.

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Aluminium does not have the fatigue resistance steels have. With stiff springs and higher RPM for drag racing, you are probably experiencing fatigue failures. IMHO if you continue to replace one rocker when one breaks, you will continue to experience weekly failures.
Top fuel teams replace Al con rods and pistons regularly for just such a reason. Blown alcohol guys buy the used parts to run at significant saving to them, and they do not stress them as much. They get a number of runs out of them and switch them out before they fail. By then they are pretty much wall art.
PM proceedure would say replace the Al rockers at about 100 runs or switch to steel rockers that have higher fatigue life.