Help with diagnosis Please

[ElementAI]

News from the Owner is not great as the car is at the Dealer with a still unknown problem.
2000 986 S w/ 44K on it.
There is a really loud Rattle/clanging from what sounds like inside of the engine like something is loose in there and rattling around inside. The noise increases as the rpm increases and is present with idle in neutral and in gear. The car starts fine and has not thrown any CEL at all no dash lights at all. Drives fine other than the really loud rattle/clanging sound. 2 Porsche indy and one dealer techs say some bearing is loose and clanging around inside and the engine will need rebuild or replacement. Porsche North America said they will not help due to age. Owner wants to have tranny dropped to see if engine run alone will still make the noise as he thinks tranny is at fault. It is not motor mounts they say.
If engine is blown Owner wants to do Electric conversion with EV concepts in SC and keep car or sell as roller. If it can be fixed relatively cheaply because it is not the engine then I can still buy it for 12K. Any ideas?? Thanks