my 03 f250 with 5.4l shot out a spark plug so i decided to replace the heads. I got everything put back together, cranked the truck and i think it sounded fine but i was distracted by all the oil that came pouring out. apparently the heads did not come with one of the oil plugs and i missed that before installing. so i installed the oil plug, added more oil, restarted the truck and heard a very noticeable tick coming from the drivers side top end. After researching and talking to friends, i firmly believe that either the valve covers are just not seated yet (i am using mobil 1 5w20) or it is a valve lash adjuster.
my question is this: will my truck be alright if i run it like this for a 100 miles or so until it should be seated? if the noise does not stop and i need to replace the lash adjuster, is there a way to tell which one needs to be replaced? i don't want to be a cheapskate to the point of hurting my truck but at the same time, i'm already in the thousands of dollars and don't want to replace them all if i don't have to.
i need to get this truck back on the road asap so any input is appreciated. thanks.

 

You sure that a cam follower didn't jump off and is not seated properly? The valve covers are on right or they would leak oil.
I would pop the valve cover back off and check the cam followers. If one is cocked it could possibly catch the retainer and pop the keepers out which could cause a valve to drop (worst case scenario). With the followers removed, the lash adjusters should just pull up out of the head and the new ones push back in. (They rarely fail though).