Stranded/ Loud knocking noise

[dray]

At the top of Raton Pass my truck started making a loud knocking noise internally in the engine. Had it towed to Pueblo Dodge where they said the # 5 or #6 piston is damaged, but the head was not pulled. The Service Writer thought the oil filter caused it. The truck is an '03 2500 4x4 quad cab w/ 170,000 miles and very well cared for. Had to return back home to Tulsa and left the truck there. Any ideas about this problem? Could it be anything other than internal damage. Can this engine be rebuilt instead of having to buy a new engine? Any help would be greatly appreciated as I am stuck w/o transportation and this has been a great truck.