Cinder blocks = bad, bad idea. I can't find a picture of the elevated ramps used for Jeep maintenance in WWII. They would hold four jeeps, and [I think] were ramped at both ends.
My thought is: If you want 2' of clearance, why not a floor jack and jack stands. When I raise a Beetle, I have a 2-ton floor jack and short and tall jack stands and do two lifts on each end.
Look at what house movers do, called cribbing, made by stacking short pieces of 2x4. Every once in a while I gather up all the 2x4 swaps and just make a section of cribbing to use them up.
Box crib - Wikipedia, the free encyclopedia