At the request of someone looking at the car, they offered to buy it, but wanted to see how it ran, to the end of the street and back. So we did. This is what we found...

Under no load, free revving, there is a deep clacking from the engine, and it sounds like the intake manifold or below, but I could be wrong, it is rather loud. Does not sound like a rocker, it is much too loud. It sounds like a bad rod bearing, or perhaps a collapsed lifter(which are Comp Cams type R with less then 3000 miles on them). Also when the throttle is blipped in neutral, it makes that funny "clackity clackity clackity" really quickly as the rpms fall down as bad rod bearings tend to sound like... But under load, ala 75% throttle and above and more then 4000rpm in gear, the clack is completly gone and the car produces a bit of power, but we didnt rev it past 5k or full WOT so dont know if it's loosing a lot of power on top end... but while driving around at low throttle and rpm in gear, it feels like it's stumbling and has a leak or something because it barely runs. So, life continues to be stupid! Any ideas once again? Is this just a really strange rod bearing that has gone and is tormenting me, or could it be something else?