Engine Tapping Noise :(

[rocco16 at sbcglobal.net (LEF)]

  So, I've got a loud tapping noise apparently coming from the exhaust valve area of my number 3 cylinder.  It started out as a slight tap above 3krpm but rapidly changed to a constant loud tapping noise.  
  Could it be a simple exhaust leak.....??????


  Obviously the head has to come off.  What parts are likely to have been damaged and need replacement?  Is the head itself damaged by this?
  Who knows which parts have been damaged?  Cam, cam followers(lifters), or valves....?  Nobody knows if the head is damaged, either...


  Also, what parts would you normally replace when rebuilding a head with no known problems?  I'm not asking for a list of gaskets - do you replace valve springs? hydraulic lifters? valve guides? 
  One wouldn't normally rebuild a head with no known problems.  Best figure on replacing everything...that way you won't be disappointed no matter what.   Lay aside about $1500, then take the girlfriend out with what will be left over..... :)

  larry
  sandiego16v