Auto Racing: Clanking engine, spark plug wire, correct terminology

Question
Okay, there isn't a section for engine repair, so I guess going to the racing guys would be the smartest idea.  However, the engine I'm talking about is old, try 40-odd years old, so it probably doesn't exactly fit in with the engines you deal with.  Still, I'm desperate.  I've got a Ford 200ci Inline Six Cylinder from a 1960s model truck.  It's recently developed a hell of a clanking noise and a gearhead friend told me it's the pushrods or rollers.  I don't even know enough to know if he's using the correct terminology, all I know is that it sounds like either a little bar that pushes one of the cylinders up has gone bad, or something that rests on top of it has.  I was wondering if you could clear up the terminology, and maybe even find me an example of what my friend was talking about.  Thanks, and good luck!

Answer
Firts off I need a little more info. When do you hear the noise? When its idling or on acceleration? Does the noise have a rythmn to it or is it random? When was the last time you changed the oil? Does the engine pop back through the carburetor?
Heres some things you can check. With the engine running pull off one spark plug wire at a time and see if the noise goes away. Onece you pull off a wire and determine that the noise is still there put the wire back on and move to the next one. If the sound goes away when you pull off a wire that is the cylinder you are having trouble with. Next I would pull the valve cover off with the engine stopped and look for loose or broken parts. Wiggle each pushrod and rocker arm to see if they are loose.
Get back to me with this info and we'll go from there.