I own a flood truck daily driver. Mine was a college kid who couldn't make the payments anymore so he "left it in neutral" when he was backing his boat down into the water.
Left it there for more than 24hrs before a "tow truck" could get to him.
In my case the fill port on the valve cover was above water level. It fried the starter and all electronics that were submerged. At the time I really couldn't afford a new let alone preowned diesel so I jumped on it.
Yes it was super cheap and I got into a truck that buddies were paying $30k for. I had to rebuild her, massage her, love on her, bypass some things, as well as deal with little quirky things. FOREVER. . . . . Lol
So my point is, yes I'm driving a nice truck but I saved money on the front end but will pay for it on the back end. Forever my title says flood damage. I lose an automatic $15k or so of value just based on that statement on my "blue" title
So if you are fine with that, rock it out. I had a trans, front and rear diff and tcase full on milk shake fluid. Tons of work and flushing out.
I'll never be able to sell it as a clean trade in. Which sucks because after all the work I have done, it's in better shape than most trucks I have seen for sale, including here, along with mileage like yours.
I wouldn't buy another one and do what I have done. Good luck