G'day lads.
With this wet weather I'm sitting here trawling the net. Found this.
Now I'm not sure if I would trust my pride and joy on these, but the chap reckons they will hold a bull dozer.
Extract:-
"Have you ever wished there was an easy way to get your Corvette up in the air so you could comfortably work under it? Here is a safe and inexpensive way to construct a set of portable ramps.
Instructions:
The ramps are indeed easy to build. Both sections are built identical. The ramps are 10'9" in length. You can construct them from 2"x10" or 2"x12". In this set I used 2"x10" and then nailed a couple of lengths of 1"x6" on each side on the bottom to give some extra lateral support. (If you use 2"x12" you will have more room to place a hydraulic jack under the frame in case you need to place jack stands under the frame). The top and bottom are 2"x10" or 12" with 2"X10" ..............................."
Click This Pic To Read The Full Article