my motor made the same exact squeel and it was 2 main bearings and 2 rod bearings spun. I had about 40 psi as soon as you start it cold then it would go straight to nothing in a few minutes and check gauges light would come on. sorry it sucks

 

The last thing you two with those ticks and knocks should be doing is revving the engine.
I agree with the first one being a rod knock and the second being valvetrain related. Not sure if the LS1 owner is still using shaft mounts or rockers with studs, but nonetheless. It's valvetrain related.

 

yea the ticks are probably valvtrain related and if they both have oil pressure problems its probably a dry drivetrain ticking. But that squeel in the second one is unmistakeable its bearings and they definately shouldn't be reving them like you said if they want to use any of their old parts in their rebuilds.

 

Wow, that first one brings back bad memories. The post looks identical to one I made about 2 years ago!
http://www.mofbody.com/forums/viewto...=16155&start=0

Definitely sounds like mine did and when I got it apart, it was at least 2 mains and I think 3 rod bearings that spun. I say, get that bad boy out and crack it open. Good luck.