We level our 32' DP using 2X10 blocks on the driveway to level so we can run the fridge for a day or two while we load up before leaving. The amount you need to raise is very difficult to guess without measuring.
If you can find the wheel base on the rig, mark that distance on the drive. Take a straight 2X4 on edge, one end at the mark on the high side, put a spirit level on top and raise the other end until it shows level. Measure down to the low mark and that will be the exact amount you will have to raise it the front end. The Rhino ramps look like they will only raise it 7 inches or so. I have found that wood ramps can slide when driving the front wheels up onto them, especially if the drive is wet. Keep off the brakes until you are up at least the first level then brake gently.
