[Ieatcamaros]

So let me get this straight. Your car knocks only at low rpm under a load? Does it knock if it is just sitting in the driveway at the same rpm? I know you said once it gets to around 2000 rpm you can't hear it, what about in the driveway? Usually with main bearing problems, when you throttle it up fast, your oil pressure will drop instead of increase. Try this and post the results.