Yesterday I went to fire up my car (it was already warm since I had used it earlier in the day) and about 10 seconds after it started I heard a snapping sound followed by it running rough. There was a consistent loud ticking noise which sounded like something hitting the inside of the valve covers. I shut it down and pulled the covers to find out both sides broke a stud clean off right beneath where the rocker mounts. They were not opposing cylinders either. #2 and 3 cyl. Also, FYI, I noticed another rocker was 'loose' on its stud, just kinda flopping around. I extracted a couple bent pushrods too. Here are (what I know of) the engine specs: Pre-'86 small block 355 (casting # 3970010) Iron Vortec heads (casting # 10239906) Comp cams 268H Edelbrock RPM Air-gap intake + #1405 600cfm carb Hooker headers So I'm wondering what the hell happened? And is it worth repairing these studs or swapping on a better set of heads? I didn't build the engine in the first place, so I'm open to any recommendations.