I have a 305 TPI car that has a metallic clanging sound that i swear is coming from the intake manifold . I put a piece of vacuum line in my ear and traced it to just under the throttle body area . Its not a knock sound , it sounds like a clanging sound , its the only way to describe it . I thought it was my alternator , timing chain , or water pump but when i put the vacuum line to them i hear nothing like this sound coming from them . I sure hope someone here has run into this before , if not im gonna have to tear down the motor

 

Have you revved the **** out of lately? Maybe a collapsed lifter/bent pushrod. I had a nice metallic clank that I couldn't pick up through the valve cover. Tightening/adjusting one rocker a lot got rid of it. I don't have a lot of experience with that problem though.

 

Nope , but that doesn't mean the previous owner didn't . I was thinking along the same lines as you or maybe the previous owner dropped a bolt or something in the intake and its clanking around in there . I have to re gasket and seal the whole motor so I might as well take the intake off and have a look . It runs great , no knocking ,no smoking ,so it really threw me off .