JJ im thinking its a really loose rocker arm. with the engine off pull the valve cover and see if you can wiggle em side to side more than normal with just your fingers. mine was making this horrendous sound you speak of and one rocker had almost completely come off. i got lucky it didnt come off or do any valve damage.

 

Chris... was it a clanking sound, or a ticking? I was able to wiggle some of the rockers side to side...

 

Rockers

 

OMFG!!!!!!!!!!! I can't believe that I'd ever hear a sound like that coming from an LT1!!!

I thought my "ticking" was bad, but it turned out to be 2 hand loose, yes.. "2 hand loose" spark plugs!! It was both an exhaust leak and a spark jump "snaping" freaking me out.. Spark was jumping cause the platinum on the ground prong was burnt off, leaving the 2 plugs gapped at .060" : /

 

after my head swap and adjusting the rockers I heard a random clacking, it would get louder with throttle input. took the valve covers off and found one rocker arm real loose.. almost to the point of the pushrod stepping out We thought we adjusted them perfectly but since the car sat for a month the lifters must've bled. I readjusted them and that clacking went away.

 

That sucks the same thing happen to me after cam install,i hoped for the best but it was a spun bearing,I dont care what anyone says the chances of spinning a bearing after a cam install are against you,there are more people that spin bearings after a cam install,than do not in an LT1 motor!!!!

 

I found the problem. It IS a bad bearing. Its at the shop now getting rebuilt. I'm just going to rebuild it back to stock, drive it for a while. Thanks for all the help guys. Add me to the list of people who spun a bearing after a cam install in a LT1. I guess the mix of bearings splashed with coolant and revving the engine higher was not a good combination.