ticking/knocking

[73 Mustang Boy]

This may sound stupid but check the plug wires. I had a knocking noise on my car for the longest time and couldnt figure it out. It would knock sometimes and and not others real weird. I checked all the rocker arms and lifters many times then one day I wiggled the plug wire while the car was running and it stopped. I bought a new set of wires and the noise was gone. I think the wire had something wrong where the wire and the boot came together or something.