Rocker Arm clatter ?

[80Bu355]

Stock 350 and one of the rock arms started clattering today. Im not the most mechanically inclined guy but im learning. I tried to adjust it out but it would stop and then come back. Im not sure what to check now? Any help or suggesting would be great. Thanks in advance!

 

[bowtie81]

bad lifter, rocker stud pulling out, bad cam lobe.

 

[80Bu355]

Guess no avoiding taking the intake off is there? ](*,) If it is the cam and I replace it with one that is just a little better than stock. Do I have to degree the cam?