my engine has made this noise since right after first startup and has continued to do it after about 400 miles, it sounds like a rocker tick that speeds up with rpm and seems loudest at cruise, i have readjusted the rockers 5 times and it still does it , my cam lobes are fine and the cam is a hyd mech comp cams 274 h with roller tip rockers, i have tried to pin point the sound but i cant seem to find it, any suggestions, someone told me that it might be my mechanicle fuel pump, also i have narrowed out the alternator and the water pump