Purchased a Budd cab 31 from an estate. It is unknown the condition of the motor. It starts good, runs good, does not leak excessive oil, no smoke. I adjusted the valves to try to eliminate tick. Have two other A's and the do not have this noise. Sounds like an exhaust leak so I installed a new manifold, gaskets and a new Aries muffler. Noise still there. Does not sound like rod knock, more like manifold leak. Suggestions????