Welcome.
I assume tapper cover side rubber refers to the cam adjuster seal which you would do as part of the valve cover gasket refresh. (tapper cover is the same thing as valve cover)
Valve guides and seals are usually looked at during a head rebuild. Sometimes they need to be replaced, sometimes not. If you can afford it, now would be a good time with the new valve job.
Hope that helps. Sorry to hear about the timing belt!



