Quote Originally Posted by V8Astro View Post
I have a comment for the mechanical part only because I've been there done that. I had the exact same thing happen to me once. I can tell by how far down the set screws are in your poly-locks that your rocker studs are too short. I'm willing to bet the little bit of broken rocker stud that was left is only 3-4 threads long. I had one pop just like that 50 miles from home once. It happened at a stop light in my case nothing but the stud and a pushrod were damaged. I ordered a set of +.200" studs. Fixed it right up
Good catch! I suppose if the rocker ball is riding on the threads instead of the shank of the stud the stresses during operation can form a crack in the threads and ultimately shear the stud.