Whats your miles?
I have back lash and slash and guns and roses in my 91 that has 142,000 km or 88,000 miles. It gets worse as it warms up here in summer.
I'm thinking about some sawdust in with the GM modified oil solution!!!
We talked about this lash before somewheres here and it was explained to me that its just happens and thats life.
I don't have the clunking noise however. Maybe its Slash's tall black hat hitting the underside of your engine cover.
tRev