Noise

After firing up engine we heard a knocking noise which seems to be coming from the oil pan. Not great news but part of the process. 

It could be a connecting rod hitting the aluminum oil pan or an oil scraper. 

We will now remove one of the plugs above one of the oil pumps and see what to do about it. 

Engine was rebuilt and no noise was heard - however it had a different oil pan on it. So we suspect it's the aluminum oil pan. 

Would hate to have to take engine out again after being 99.9% done but let's see. ...