How can I install a waste disposer if I have a high drain fitting?
Interesting problem.  I'm afraid that having a high drain will cause you a lot of problems. My greatest concern is that the disposer will not drain fully and the standing water and waste will cause bacteria growth and foul odors.  This could be very unhealthy in a kitchen area, not to mention unpleasant. I'd look at a way to lower the drain if possible to assure proper drainage.