The timing chain has never been replaced on my 85 190E 2.3 8v.

Are these all parts that should be replaced or can I get away with just replacing the chain? What do you recommend?

Timing chain
Timing tensioner
Timing Rail Pivot Pin
Timing Guide Rail
Timing cover gasket

Also if you can tell me how many parts of each I need.
Is this a hard job to do and how long do you think it would take for a DIYer?



Thanks