Motorcycle Repair: 74 Shovelhead knock, valve train, rocker arm

Question
Hey buddy, I have a 1974 Shovelhead and the other day I heard a hollow knock in the rear head, not a rod knock knock knock with rythym but an occasional one. I checked compression and its good, I checked pushrod adjustment and its good also. The bike still runs great but I cant specify exactly where it is coming from. If you have any ideas, shoot them my way because next step is the shop. Thanks

Answer
Kyle,can you isolate the noise to a cylinder or head or the upper part like the valve train area. Untill the noise can be located to a specific area it tough to say its this problem and be accurate. Sorry it could be as simple as the gap between the rocker arm and the valve stem.