Leveling TC

3 sets of Lynx Lego blocks. I like to have the TC absolutely level within 1/2" so the shower drains well. I have 2 bubble levels in the cab of the truck so I can determine how many blocks to use before even getting out. I've broken 2 of the blocks in 2 years vs. almost all the Camco yellow ones in 2 trips! Those were barely adequate for my TT that had about 1,000 lbs / tire, but are too fragile for the 2,000 lbs per tire that I am running with the TC rig.