I was just re-reading the add and looking at the pictures. That text seems fishy to me. Who would swap out an engine just because changing the fuel filter didn't fix it? Especially if you had to swap out the IP, Flywheel, oil presure sender, top bolt from the thermostat housing, and all the accessories and bracketry to another engine. No, I think this engine maybe a little sicker than the seller indicates. Too that end, I contacted Rumor central. I have new information. This may be an engine with a compression problem. Turns out another individual in the area came in with a miss to inquire what it would take to fix it. After a compression test, they were told "more than you would want to put into it" They were given information on an engine that could be had for $800 out of an ambulance that was out of service. Hmmm.... Could it be that Joe has bought a copy of what he already had?