I made wedges to go under mine. They raise the rear of the seat about 2". I did them to get the angle of the seat back parallel with the rear bulkhead, which allowed the seats to go back farther. I originally had seat sliders too, but I removed them. My wife wasn't interested in drving the car and the seat was a bit too high with the wedges and the sliders.
To simulate the wedges, throw a piece of 2x4 under the back end of the seat and see how it feels.
Jim