I am replacing my timing cover gasket. Is there anything else I should replace. I was thinking of replacing the timing chain. I 'm not sure if it has ever been replaced.

Also my car vibrates real bad at idle. My car is idling at ~1100 and I know where my vaccum leak is at. Everything vibrates and I was wondering if it is the harmonic balancer?

 

replace the timming chain and both sprokets, your gonna need a puller to remove the crank sproket. and when you put it back on get a striaght edge and line the two dots up perfect with the new chain back on. otherwise you will never get your timming right.