2004 Jeep 2.4, Chrysler I-4

I don’t. Stuff happens. Even unusual stuff. And people don’t always “fess up”, hoping a mechanic (or in this case neighbor) will somehow find a simple solution and they won’t have to disclose the true story. I guess that’s human nature for some folks.

I wish you (them) the best of luck with this. If it gets started again, I’d avoid standing behind it. If that mud scored the cylinders, it’ll look like someone threw a smoke bomb.

You might want to suggest to your neighbor that if they decide to build another mudmobile, they consider an intake that raises the intake opening above the roofline, or at least above the bottom of the windshield. You can see these on some military vehicles and vehicles built for serious off roading. A magazine specific to this hobby should show some sources.

Would the block from a Sebring, which is mounted transversely, have the same motor mount points?

Front wheel drive and rear wheel drive blocks are different. A remanufactured Mopar short block is $1180 plus core charge, it may not be worth the effort in looking for a compatible car engine.

https://parts.allmoparparts.com/oem-parts/mopar-short-block-rl134136ac

Sounds like there was some kind of hydro-lock problem that damaged the crank. I think however what I’d do , since the engine has to come out anyway, first remove the transmission/& torque converter, see if the lack of attached tranny changes the amount of binding at all. I don’t see how it could, but an easy enough experiment to do.

As far as replacing the engine, sounds like a fun winter-time garage project.