I don't use any blocks under my wheels any more. The level-up takes care of it so far. But if your rig is 4 or 5 or more inches off side to side it wouldn't hurt to throw down some blocks under the wheels and then add a couple under the level-up legs also. That is a lot of space to make up for other wise.
The last time I set up a good friend of mine, who is also an RV'er, was with us. He was dying to see how the level-up worked. I hit the Auto-Level button and he watched intently. 2 minutes later after it finished I looked at him and ask "Well, what do you think?" He looked straight at me and said "I Hate You!" He then turned and walked away. Hate to admit it but I had the biggest smile on my face.
