You SHOULD be able to raise it that much. I raised mine 2" by having a spacer welded into the frame between it and the axle that lifted it 1-1/2" and then I was able to mount larger tires that added another 1/2". I talk about it in this thread: https://www.hilotrailerforum.com/f19...12/index2.html
, starting in Post #24. (I also had the axle moved forward about 3" as I recall, because it was originally too far back. My axle is the torsion bar type, but a similar mod could be done if yours has leaf springs.
A few other members have also added spacers to raise their trailers too, and I don't recall anyone reporting adverse effects.