I think what's already been said is good advice. 400 miles isn't that bad really so just make sure your bearings are good, tires good, brakes, and a spare tire.
I would also recommend strapping the back of the boat to the trailer with some straps. Although pretty rare, if you get in an accident, you want the boat to remain on the trailer and NOT into your truck.
Thanks "SP".....I've done a lot of towing up to Idaho with a single axle without any problems. I've just switched to a double for a little more comfort towing that far. I think the advice above is great.
One last thing....if you are towing in bad weather/gravel/etc. the idea of some mudflaps is a great idea. I have not done it personally but I would love to do so in the future. Gravel can kick up and put small chips in your gelcoat.
1994 205, LT1