Do you mean rear anti sway bar??
My son built a off road tent trailer, like the Aussies use, in fact it has an Oz Trail tent on it. He had put up with tail wagging until he changed the axel around. Trailer axels should have both camber and toe-in, so that's why their orientation is important. It chews tires but they drag sweet. They are bow legged and pigeon toed.
Another way to deal with weight transfer, with a higher center of gravity that's what you dealing with, is to add a second main to the spring packs. When I had wet bolts put on our spring packs ,I had them add a fourth leaf to the pack. But it was the bottom small one, not enough.
