I just rebuilt the 350 in my 86 Z and only when it is cold it makes a weird clunking noise that sounds like it is coming from the passenger side head, I think i might of tighten a rocker to tight or something but im not sure. once its been running for about 5minutes and warms up the noise goes away. Oh yea and it only makes it when you rev the engine to 2grand or more.
Any help would be appreciated.

 

I wouldn't describe a valve train lash noise as a "clunk", but as more of a "tap" or "click". If the noise is a dull knock or "thud", start looking at other possibilities - unless the valves are touching off the piston tops.