Took my cammed 6.0 out for a little drive, parked it and poped the hood and theres a loud top end noise. its hard to tell what it is. Iv'e only had the cam and single beehive springs in for about 4,500 miles. Surly its not the lifters cause the truck only has 43,000 miles on it. But i guess it could be anything. ideas?

 

Just listen to noise and determine if its at cam speed or crank speed. 2-1 crank to cam speed. This will help give you a better idea if its lower or top end.