I would like some info on what is the best way to tell if pushrods and rockers are worn other than the obvious. I have a tick in my 340 duster and not sure if it is the valvetrain or maybe just header gasket?
Thanks
Cory

check p/r on a flat surface to see if bent .if rockers have many miles on them then mayby the cup end is bigger try and see if the p/r tip fits snuggly and go from there.

Headers you say? THAT'S your problem.

You can use a stethascope (long screwdriver w the handle pushing your ear closed) to listen to different areas and pinpoint mrtal on metal noises. A piece of 3/8" oil line hose is good for listening to header leaks. If its a coiled hose its even better you can use the curved end to snake around and under the tubes. If its leaking you'll find it w/ the hose. Don't forget to check around the collector junction where the tubes meet for bad welds or cracks.