Ticking 340

i doubt the cam thrust plate is coming loose and being it is a 340 it will have a double roller timing chain but it could be hitting the timing cove if it is too loose you can pull the fuel pump and reach a finger in there to see how loose it has gotten anything more than half an inch is probably too loose. you can use a long screwdriver and touch it to various places on the engine while it is running and listen, you can also remove the fan belts and listen to it for a lil while and see if the noise is in the accessories