2-3" isn't ideal, but it isn't too bad either. Geometry wise, all it does is lower the rear roll center height half the space of the blocks. With SS springs the front segment is so stiff, the blocks have a negligible impact on flex.
I use a 2" block on my F body that is taper cut to set pinion angle. I put around 400 hp to the ground with set up and launch it at 4500 rpm. Never had any issue with spring wrap up or wheel hop with this set up. It is hard to see in this pic, but notice where the axle tube is in relationship to the spring pack.