If you are handy with a wrench you may want to check this out yourself. Remove the valve cover that is handiest and rotate the engine with a socket on the dampner bolt head. Follow the normal direction of the engine rotation (look at the cooling fan blades). Carefully rotate steadily with constant pressure until the cam mark lines up with the cam tower mark. Note the indication of timing on the dampner wheel (you may need to do this several rotations until the cam mark lines up and the dampner marks are visible, remove spark plugs to unload compression and engine will turn easier). After you have determined a timing mark on the dampner, reverse the direction very slowly until the cam start movement in the opposite direction, note the position of the dampner timing mark. What is the difference. There is no set amount of allowable play that is published but I would not like to operate an engine with over a 5 (I have read 10) degrees difference.