At this point you need to cut the oil filter open and roll out and inspect the paper element inside of it. If it's full of debris and your scarred by what you see, you need to just pull the engine back apart, and the noise should be obvious once you do. You'll need a hacksaw to separate the element from the internal structure that it's attached to on the inside, but cut it up high where the threaded portion is that spins on the block. Oil goes to the inside center of the filter first, so once you get it rolled out, inspect the inside of the paper first. But it might be so full of trash without doing that that it will indicate an obvious internal problem. Take pics of it and post them.
