Must be a late 07 which in the auto world is an 08.
No mistaking the differant fenders and headlights.
The bad news is an engine from an earlier 04-07 wont work in the 08.
Hum. I have a low milage 4.7 from an 08 Dakota. ;.)

 

First, I'm really sorry for OP's lapse of judgement. Probably your 07 (or 08, whatever) cost enough that you're making payments so you can't reasonably walk away. And I'd suspect that the damage done won't be covered by insurance--not intended use and all that. So the OP is on the hook. & it's gonna get spendy.

In addition to thrashing the engine, probably a bunch of the wiring, electronics, the starter, the a/c (possibly,) power steering, and the transmission are damaged. If the truck got in deep enough to suck sandy water in through the air intake, it got in deep enough to get a load of the crap into the transmission.

I'm the reality check guy around here, I guess. If the OP can do his own work, he and his brother (his partner in crime) can try to source all the parts from wrecking yards and resurrect the poor thing. I wouldn't bother with a rebuild--that engine's so gonna have damage beyond just a thrown rod. And if the trans did suck in a bunch of dirty water, the OP may be able to drain and flush it--but probably will need to have the trans. rebuilt.

And in the spirit of reality, I wouldn't change to a V8 of any stripe. Keep It Simple (stupid!) Yeah, nice to contemplate putting a 4.7 or 5.7 in, but it's really gonna add to the complexity and expense at hand.

And if the OP can't do his own work? Max out a credit card or two and have it fixed. Or consider defaulting on a car loan (with all the really nasty consequences.)

Again, sorry dood! It kinda makes me sick to the stomach to think about it. . .

 

The rest of the components may not be toast.
I used to play in the mud and up here on the wet coast we have lots of it.
The truck would have pushed a wave which would easily get up into the air intake since its through the passenger fender well.
The ECM and other electronics would have been behind the wave and not under water.
The water line is well below the electronics and even the top of the engine.
It may have just taken one gulp of water which snapped the rod and shut down the engine.
Hose the sucker out well and check for water in the trans, diffs, PS pump and see what you find.
This was fresh water I assume so as long as the starter and alt are flushed out well and sprayed with a water displacing oil like "fluid film" they should be OK. I spray that s..t on everything!
I spent 18 years as a marine mechanic and saw a LOT of sunk boat parts in salt water. As long as they were flushed well and oiled up most of the time they would run well for years after.
Our trucks have pretty well sealed electronics and wiring harnesses. Mite just need a replacement engine from the auto wreckers or a rebuilt long block.
I would not just let it sit. Hose it out/off really well, clean up and save what you can ASAP.
Keep us posted and good luck.

 

I sunk an old gas bulldozer before and had it pulled out of the pond and allowed it to dry for a few days. When I knew the electronic parts we dry enough to operate I removed the spark plugs and cranked the engine to pump any water out of the cylinders, then vacuumed the remaining water threw the holes. Then flushed the engine and transmission oil and it was as good as new. However if you tried to crank the engine full of water, there's a good chance you broke something.

 

Finally got my truck back last Saturday! Put a regular 3.7 v6 in there. Just happy to have it back! Found a engine that only cost me 1,000. She runs great. Still have scrubbing from my new tires but once that's fixed she's gonna be a beaut. Thanks for all the help guys new pics coming up shortly!

 

I'd say go old school, do a 5.9 swap. But if you got the v6 and are happy to be driving it again, then that's good. Pictures please