At first, hello to everybody from Finland!

I've been searching the cause of my 350 ticking sound. Found 2. Cyl rocker arm had notable side movement. Bolt was tight and there were no vertical movement. Took rocker arm off and noticed that exhaust? valve had almost went through retainer.



Took retainer off and found these. Locks were sharp as a blade!

Catastrophe avoided? Put new locks and rotator cap and
hopefully ticking sound is now away. But what would cause this? Is there any other things that should be checked?

 

How many miles on the motor? You could have a burnt exhaust seat causing the keeper to wear. Does that valve move all the way up and down smoothly?

 

I have to say that I don't have any clue about mileage. It's not original and previous owner did the swap.

Valve moves smoothly. I think that burned/leaking exhaust valve should make own sound to the exhaust pipe?

 

Do a compression test on all cylinders, that should tell you if there are problems with valves leaking.
also look over the rest of the retainers there could be more bad ones.