68 valiant project....440 tapping ticking sound at 2500 rpms and up

[investigator]

Title says it. This is a new engine that was tuned on the dyno. Since getting it in the car i have had this noise. I thought it was an exhaust leak, but now im not sure. If it is it would have to be on the header flange, I've checked everywhere else. I do not hear the sound at idle. It is heard in park and under load. Any thoughts or input would be appreciated. Video below.

Take an extremely long screwdriver place the handle end on your ear pushing you ear closed and the metal tip on various parts that you want to check it will carry the sound like a stethoscope should tell you where the ticking is. Good luck. Also Harbor Freight actually sells engine stethoscope very cheap less than 15

 

[68dodge]

Start the motor cold, have someone help check around your headers for leaks with your hand before it gets to hot.