On my GS VISA 19RGU, I was able to find the axle manufacturer's label on the axle. It was a Lippert diamond torsion axle. I searched etrailer.com and found the correct axle riser. The riser channels install between axle and trailer frame to increase deck ride height. The cost of the axle riser kit was $64.95. I got free shipping because I added enough other items to get the total bill above $99. I had thought I could do it myself but once I started, I realized I didn't have the heavy duty tools needed to unbolt the axle from the frame and reinstall it. I found a local shop that specializes in hitch installation and trailer sales. They installed the axle riser and only charged me for 1.5 hours labor. With taxes etc. it was $165.00 for the install. The riser lifted the frame of the trailer about 3.5 inches. Now I have no scraping when pulling in and out of my driveway and the sewer connection is high enough off the ground that I can now easily attach the hose and empty the tanks.
Very pleased with how this improves the functionality of our VISA.
Link to riser kit. (Note there are two basic types of Lippert 3500 lb. torsion axles listed - a square style and diamond style. Be sure to verify which version your set up requires before ordering.)
https://www.etrailer.com/Accessories.../LC270682.html