sorry, i have missed a bit of this thread as i have been busy in school with exams and so on.
what did you find/did you take apart the oil filter?
have you/someone had the lifters out and changed them for different lifters?
i would doubt that a rocker is physically moving around in the motor when running, if it was, there would be some serious marks on the valve cover etc.
if the lifters are gone, or it is something in the valve train, but the motor seems to be running half decent and not missing/backfiring. this usually means that all the valves are still opening. they definatly are not performing well obviously, but there is SOME lift, letting the truck run.
aside from all the racket...how is the truck running? rough/vibrations?
low idle?
poor throttle response off idle?
...the valve train WILL know when more gas is applied even if the engine rpms arent increased instantly.
its like riding a bike, your chain wont skip until you really push hard on the pedels...your speed hasn't increased yet, but there is that much more stress on the chain etc.
...then you fall on your face
