2016 peterbilt 579

[Rawze]

head gaskets do not fail without liner issues... that truck needs an inframe and the block counter-bored, liners raised to at least 0.014" .... the whole nine yards. I don't give it 40k miles and that head gasket will blow a second time.

most likely the thing blew the head gasket... owner got the bad news and put a head gasket on it and is trying to unload it on someone before she blows out again.

the truck is worth maybe 12k - 14k on a good day with it in that shape.

you never mentioned the rear axle ratio... how much you want to bet its geared tall and its been lugged to death its whole life ,... and that is what killed the engine. That or its deleted and has a bad delete program in it... or .. perhaps both.