Those trucks you see fording rivers to that extent are usually diesels.I do have all the wheel well covers on. The lower skid plate is on as well. What do the guys use that ford the rivers and stuff? What good is a snorkel if your distributor shorts out?
Look at your O2 sensor plugs underneath. They are known to be a problem when wet.
There is a rubber o-ring that is supposed to be on the distributor cap. Does yours have it?