With only a quart and a half in there, and dark to boot, my feeling is that some engine damage has occurred. It takes more than a quart and a half to fill up oil galleys along with pooling and oil clinging to various areas so this means the pump is drawing some air.
The clicking in the top end could be caused by the valve lash adjusters suffering some damage. Mitsubishis, and some other vehicles that use the same adjuster, have been prone to the ends of the lash adjuster wearing through anyway even when the oil has been kept full. When very low on oil the disentegration process is even faster.
This is what they look like.
http://www.partsamerica.com/ProductDetail.aspx?MfrCode=BAR&MfrPartNumber=0227000
As you look at the pic, they usually fail on the left end there. When removed from the valve train any damage is easily noticed.
The SeaFoam or Marvel Mystery Oil treatment is something to be considered before tearing into it anyway on the offchance an adjuster or two could be sticking.
(Failure of these adjusters is pretty common anyway. I tore into 3 Mitsubishi engines (total of 24 adjusters altogether) and there was about 6 good ones out of the entire lot.)