If you have leaf springs and they are under the axles, they can be relocated to the top of the axle. This is generally referred to as "flipping the axles". Here is a conversion kit for Dexter suspensions:
If the leaf springs are already above the axles, you will need to have a sub-frame installed between the spring hangers and the trailer frame. Although there are those which install blocks between the axles and leaf springs, this is not recommended.
With the AL-KO Rubber Torsion axles there are two choices. The first, which Lou addressed, is a sub-frame. This may have frame warranty issues and adds more weight to the trailer and the axles which may be an issue if you are close to capacity. The other option which, I am pursuing, is to replace the axles with axles which have a different drop arm degree. Al-Ko makes them with different degrees on the drop arms and a corresponding lift or drop in the trailer height.
CAUTION: I am providing this information, however one must be careful and informed about any decision they make to lift their trailer as it can result in stability issues if not done properly or if lifted to high.
Glenn & Beth (Dad & Mom)
David & Audra (12 year old twins)
2006 Dodge Power Wagon (Adventure & Tow Vehicle)
2006 Rockwood 8281SS (Home away from Home)