I have a 355 in my Camaro had some rocker arm noise , checked and one of my pined studs broke so I put in a screw in stud and it starts up fine idles good but when I get down on it act like its missing or a back fire not sure ?

 

1) Valve stem could have bent.
2) Push rod could have bent.
3) Neither, but you could have your valve lash mis-adjusted.
The stem may have pushed out for a reason, if something is binding up for instance.
You also could have valve springs that are too stiff for the press in studs to tolerate, and this one might not be the only one to pop.

 

I have about 4000 miles on motor and this is the first thing to be bad