If the crank on my 2010 Dodge Ram 1500 won't turn, what's wrong with it? What can be done to fix it?

Somehow water got into my fuel system and I had to replace the fuel pump, fuel rail, two injectors, all the spark plugs as well as the battery. After all the parts were ordered and replaced, the truck won't start. The mechanic says the "crank won't turn". He said water got into the cylinder and excess buildup over a long period of time caused the crank to "freeze" in place. He suggested to take out the engine, drop the crank and take a look at the piston rings also to see if they've been damaged.