what could be causing this
 

this has happened twice, i over reved the engine about a month ago and one of the rockers backed out and was very loose, it was ticking bad, after tightening back down tick went away and came right back in minuttes, the second time we did them with the engine running and got them quiet, we cut the car off put the valve cover back on and sstarted the car and the ticking was loud as hell ????? what is going on we can get them quiet but after i cut the car off and cut it back on the ticking comes back, any help would be appreciated

Is the car still running strong though?

Could be a bad lifter or bent valve, bad lifters will tick. You can take that lifter out and put it in a vise (wrapped in a rag so it doesn't damage the roller of the other side of the lifter)and put a small nut that just fits inside the spring clip, thenslowly compress it to get all the oil out to see if it sticks or pumps back up like it should. If the lifter stays down it is trash. You can only compress it small amounts at a time but this is the only way I know how to test a lifet

it still runs strong just the annoying *** ticking sound

just out of curiosity have you checked for valve cover clearance because you said that it came back right when you put the valve cover back on.

double check

hope it helps..
adam