I've just gone back and read the thread from the start. I wish Wammers was available as he's the expert.
My thoughts for what they are worth. I think Tomcat could be onto something with the cat. The clunk on hard acceleration could be the matrix in the cat being thrown back and blocking it if it is loose.
Next, if that isn't the noise and it isn't the turbo actuator (normally pretty reliable and you can check and clean it when you remove the cat section to test Tomcat's theory), I am wondering about a crack in the flex-plate? Or would you hear that all the time? @jamesmartin is the expert there.
Finally, what oil are you running in it?
My thoughts for what they are worth. I think Tomcat could be onto something with the cat. The clunk on hard acceleration could be the matrix in the cat being thrown back and blocking it if it is loose.
Next, if that isn't the noise and it isn't the turbo actuator (normally pretty reliable and you can check and clean it when you remove the cat section to test Tomcat's theory), I am wondering about a crack in the flex-plate? Or would you hear that all the time? @jamesmartin is the expert there.
Finally, what oil are you running in it?