I have the blocks and they work.  it is just hard when, lets say, the front driver's side needs to come up 3 blocks and the front passenger side has to come up 2 blocks. then,  of course, you have the dually's to deal with on one side.  I made a 2x8" ramp for my 5th wheel and that worked great. however, with a B+ or C, I would need 3 boards:2 for the duallys, and potentially one for one of the front tires.  Plus I would need blocks.  that is a lot of stuff and weight to be caring around.