During many years of truck camper RVing I used many blocks and built ramps up to stupefying heights to level various rigs. I even used boards as ramps to level our '95 Endeavor DP--but it had springs and no slide outs. Now with our 38' Cayman we do have slides and while it is a medium weight DP GVW 29,000 lbs, I have decided my blocking/ramping days are done. I will place a block of wood or plywood on the ground to keep a corner from lifting a wheel completely off the ground, but that is the extent of it. We are now dealing with too much weight as well as changing the geometry of the opening of the slides by twisting the frame and then perhaps expecting a rectangular slide to fit into something that's no longer rectangular and that could lead to problems. If a site is not pretty close to level, I will not set up there. Yeah, getting old I guess.
Frank W. '09 Cayman 38 SBD '08 CRV
Lake City, Florida