I'm assuming what you are describing is you have Torflex axles in place of leaf spring axles.
Dexter Axle - Trailer Axles and Running Gear Components - Resource Library
The link above is to Dexter Axle. Select TorFlex information and you can down load a spec sheet. Page 20 of the PDf shows the 3,500# rated axles which I'm assuming is on your model.
It those are the axles you have, they are more complex to raise like a leaf spring over/under kit does.
From what I know you have to have a frame shop create a structural spacer to raise the axle mount to the camper. It has to be substantial in strength and they may or may not want do it.
The only next alternative is to buy a new axle with a different axle starting angle to raise the camper. The weld the axle stub with the rubber to the axle arm with the wheel spindle at a different angle and it raises the trailer.
Lifting the rubber ride, aka torsion, aka Torflex (By Dexter) axles is tuff compared to the simpler leaf spring setup.
Hope this helps
Here are 2 posts on this topic as we have a member have higher up torsion axles come direct from Sunline
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
Google Custom Search For Sunline Owners Club