Another question, I have been looking at hitches to buy and was wondering if a load distribution hitch was a requirement to use with sway bars on a trailer. I see that they are sold seperate or as a group. I don't feel I need a load distribution hitch unless it's a necessary thing to have, for safety or other reasons.
If my memory is correct, your Overlander is a '61 model, and while a little lighter than my '64 from the factory the two coaches are likely quite similar when loaded - - in fact, if your coach has the front water tank (below the lounge), your tongue weight could actually be a bit higher than mine. The figure that you mention (400 pounds) is what my coach had empty and without options - - by the time options, fluids, and possessions carried are added in my tongue weight is close to 750 pounds (I have upgraded to 40 pound Worthington Aluminum LP cylinders) - - the trailer's gross weight approaches 6,100 pounds unless I am very careful about the Rally suupplies carried.
Even at 400 pounds on the tongue, I would recommend the Reese Strait-Line Hitch. I have used this hitch for more than 40,000 miles on my Overlander, and also have one for my Minuet 6.0 Metre. This hitch includes the Dual Cam Sway Control and results in a very stable towing relationship with both my '99 K2500 Suburban (10,000 pound trailer towing package) as well as with the '75 Cadillac Eldorado Convertible (6,000 pound trailer towing package). One of the critical considerations with having a good functioning Dual Cam Sway Control is to have weight distribution bars that are very close in rating to the actual hitch weight; proper ball height and angle are also critical to the function of any hitch system selected.
You can find more information about the Reese Strait-Line Hitch at:
Reese Strait-Line Hitch
Good luck with your hitch selection!