ticking at high rpm

Well i took off a valve cover and ran the motor till hot..The thing sounded like all the lifters were ticking a little, but when at the high rpm...4500..I start hearing 1 loud tick above all others.. Plenty of oil coming out of the pushrods so I assume it is going through the lifters properly..I guess maybe the shorter pushrods might be the answer?
I probably should go ahead and take off the intake and look at the cam though.