The riser block did exactly what was expected. It would be nice to have a riser for the rear sucker as well as in my application, where I hang the bike off the back glass of an SUV which has a slope to the glass, a 2 inch rear wheel riser (or more) would make it fit perfectly.
With my current setup, I probably have less than half an inch clearance at the chain ring. The other day when I had a flat rear tire, I could not mount the bike as the chain ring was resting on the trunk.