Mopar magazine once ran an article about retrieval of a Dodge 4x4 that had been submerged for 12 years and it was restored. I have personally seen vehicles pulled from the lake after several days and been restored.
Start by draining all the fluids, motor oil, transmission and differentials.
Remove the distributor cap and dry out the distributor. The spark plugs will need to be removed to get water off the top of the pistons. The gas tank will probably have to be drained. When you get all the fluids cleaned of water, crank it over to blow the rest of the water off the pistons.
Now is the time to determine water damage to the electronics. If it fires, chances are it will run.
There is one thing that is hardest to do in such an endeavor. That is to get the smell of fish out of the upholstery. All the upholstery and carpet will need changing.