When is time to replace timing chain. As I understand never unless it get bad. What are symptoms of bad chain. I ask because it is interference engine and I read at Internet about a couple chain breakage for F series.
Related I was called recently to help adjust timing belt to someone who didn’t set mark before removing of belt. I miss for only one tooth and car hesitate in idle. Found at internet one tooth miss - hesitation, starting problem, 2 teeth miss - valve kiss piston, 3 teeth miss - bend valve. Is it that possible. I always thought a few teeth miss no big dill.

 

Your mixing chains with belts.
If your talking about a v8, they have two chains.
Never heard of v8 chain breakage not to say is has not happened.
Unless you have an issue with either chain tensioner (there are two), there is no reason to change them.
Wear is automaticly taken up.
When changing V8 chains they must be dead on because one cam gear is used to time fuel injection off the driver side cam sensor and cam gear.
Good luck.

 

Excellent