well if the person put nitrous on it ... and a chip ... chances are that motors internals has seen daylight and it is for sale after the cheapest repair possible was performed on it ...

the chip advances timing to a point where the shot of nitrous (over 100 hp shot) it would have required to get to 350 whp would have been very likely enough to detonate the thing till a new window emerged in the block...

hopefully its just a bad lie and it really is just a NA chipped xf that has not seen this kind of destruction ...