first of all change your oil.....10w-30 isn't the proper oil for these motors, go 5w-20 and use something with some data behind it like royal purple and see if your tick is still there. Can it be heard from the engine bay with the hood up or do you hear it louder from the drivers side fender well? let me know
Hate to be the bringer of bad news but listen closely to the drivers side head....more than likely the one of the driver's side valve guides is worn and causing the noise.....at least a machine shop visit for the head is in order
+1. It comes from worn valve guide(s). Suppose to be on Cobras that have a build date before 1 Nov 2002, but if it doesn't happen within the first few thousands miles, you either don't have it or that's not the problem your experiencing.