Thanks for the advice. I use AWD with my open trailer all the time. With folks using studs in the winter a lot of the roads have pretty noticeable ruts. When I pick up our 4 tons of pellets every year without the AWD the trailer would hunt without the bars.
Most of the newer trailers have very shallow v noses, so this may not be a problem with the weight distributing bars, but measure first! On my 2000 model I was able to trim the aluminum slightly and used the bolt on hooks to the frame. More trouble to hook up the chains (have to use a jack) but works just fine.