drwwicks: "In addition to a few sections of the 2x8 I also carry a few 1x8 to fine tuned the level. The get used under the tires and jacks when a 2x8 is too thick."
I carry a bunch of lumber with me, pretty much all the time. All are 2x6 or 2x8 boards. I've considered carrying 1x? for some time, but some how just never tossed one in my pile. Probably because everything I'm using is treated lumber and I've been using these same boards for the last 20 years, beginning from my pop-up camper days. Maybe some day I'll finally get a treated 1x? scrap I can toss in my mix.
Meanwhile, I found that with tandem axles, if a 2x? is placed under both tires on one side, and its off just about a 1x? height, I can usually put a 2x? under one tire on top of the longer board under it. This raises one wheel by 2 inches (approximately) and the over all lift on the camper on that side equals to about the 1 inch (half). Anyway, for me, this works pretty well. I suppose if I had the 1x? boards, I could fine tune it to a 1/2 inch variance.
But, I've also found that just tightening the leveling jacks good and tight will atone for that extra 1/2 inch too.
Anyway, this is good advise, carry the 1x? along with you also.
I still say, there is nothing better than good old treated lumber under your tires. Solid, makes a nice foot print, doesn't sink in the ground (especially if parking on grass or dirt, and especially if on dirt or grass and expecting rain). Hallow linkx Lego blocks will require the first layer on the ground to sink an inch as that edge settles into the ground. On pavement it will work OK, but on asphalt, all that weight on those sharp edges, could cause the asphalt to dimple too. That's why I've always stuck with nice heavy lumber. (and yes, I did try the Lego Blocks and didn't like them).
But, we all do it our own way, and there is nothing wrong with that. That's the beauty of this life style, there is no right or wrong, it's just "different" for every person. All we can do is share our experiences and maybe someone will find a different or a more convenient way form them to do it too.
The down side of carrying lumber is the space it requires. But I have no problem with my pick-up truck with the shell on the bed with the side tool boxes with 2 shelves on each side the entire length of the 8 foot shell. That's 32 feet of shelf space. That carries a LOT of lumber that takes no space form the floor of the bed of the truck or the inside of the camper!
To each his own... Happy camping!