By cribbing, do you mean those sets of 2x6s under the wheels? It looks like you alternated direction each layer and probably screwed them together, right?
I did exactly that except with 2x4s. They are about a 12" cube. It's a very strong design. If you build some, make sure your jack will lift the car high enough so that they'll go under the dangling front wheels. :rolleyes:
