Randomly dies after engine swap

[Dskansas]

I have a chance to buy a very clean 2007 cheap. The owner said he had his mechanic swap out the high mileage 6.0 with a low mileage 6.0. He says it starts and runs fine and then just randomly dies. It immediately starts back up and goes for a few days before doing it again. The truck is two states away so I wanted to get some opinions from this forum first. He did send me video of it starting and running.

 

He took it to a different mechanic that told him it could be the ECM. If it is an ECM issue and I can’t get the VIN from the donor vehicle should I just run the other direction? Thanks in advance!

[CamGTP]

Unlikely that it's a PCM problem. Sounds more like a bad crank sensor to me but that is just a guess. Bad crank sensors do that exact same thing.

 

And the VIN means absolutely nothing here, the VIN doesn't change how the vehicle runs. If the engines are the same engines in this swap, the computer would run it no problem.

[Dskansas]

Thanks, I had read that on other threads with similar issues. Also read it’s kind of a PITA to do. So, if that were the issue, would you hesitate driving it 5 hours to get it home? I know the preferred method is to trailer it, just don’t have the equipment. 

[CamGTP]

It's a really simple repair in all honesty, 2 bolts to drop the starter out of the way and it's right there.

 

I'd probably still drive it.

[Dskansas]

Perfect, thanks again!