I experienced a failure on one aluminum rocker arm on Monday. See attached picture. The rocker arm split in half right where the adjusting screw is. The engine is a 383 big block, with a .550 lift mechanical roller cam and matching double springs on ported cast iron heads. My set of roller rockers is from Hughes Engines, but this post is not meant to knock them. It is merely to get some feedback on what I should do. The failure occurred right off of idle, as I was SLOWLY accelerating from a stop sign. Out of nowhere a loud ticking noise developed, and I knew it was wrench time.

So if one rocker arm failed, should I be concerned that the others might fail? The engine has about 5,000 miles on it. All of the other rockers look OK (no signs of stress cracking or fatigue). Should a person not run aluminum rocker arms with a roller cam? Or is this an isolated incident? Should I check the head for something weird (stuck valve or something?). In an ideal world I would replace the one rocker and get back on the road, but more importantly, I want to do what it takes to not have future failures.