1984 sundowner engine noise. Timing help

Hey guys, new member here. Recently purchased a 84 sundowner and don't know much about it. Runs rough and motor is noisy. Doesn't seem like a rod knock. Precious owner thinks it slipped a tooth on the timing chain. I pulled the valve cover to inspect things. I noticed 2 off colored links on the timing chain. Is the arrow on the cam gear supposed to be centered between the 2 links? It is currently centered below one of the links. I will post pictures once I figure out how. Thanks in advance.

Nick

It would help if you posted how many miles are on the engine. Maybe there is enough slack in one of the chains to cause rattling. You can take a 5/16 hose and run one end to your ear and set the other end against other parts of the motor to help locate where the noise is coming from. From the little bit of research I have done on your motor the two plated links center the crank sprocket where a dimple in the sprocket sets between them during initial build, so lining them up on the cam sprocket isn't an isssue. Personally, I would think if the chain has jumped one tooth it would have taken out the exhaust valves on the head.

It occurred to me suggest that perhaps what you are hearing is detonation, caused by pre-ignition carbon build up in your combustion chambers; Anything could be possible in a 33 year old engine. Maybe the EGR valve is not working and that would lead to higher than normal combustion temperatures. Check your timing and you could retard it enough to test to see if the rattling goes away. If you pull the spark plugs they might show a heavy build up of carbon.