Re: possiblly timing chain?
yes sir, it's the timing chain tensioner guides that are worn out! You've got to remember that a P71 will have much more internal wear than a civilian crown because the engines run much longer regardless of the miles. I just replaced mine and just in time too. Typically by the time you can clearly hear the rattling, the guides and tensioner guides are shot! You'll need a "timing set" valve cover gaskets, front cover gasket set and go ahead and put a water pump in it while you're in it. I got my timing set on-line it was a hell-of-a-lot cheaper. Cloyes set from "Rock Auto".