Anybody have experience driving a Crown Supercoach with a Detroit 6-71 in a tandem rear? This would be a heavy 40' bus with 3 axles; and my fear is that it will perform poorly in hilly terrain. Any real life experience? Bus is pretty far away, so I'd like to get an idea of drivability before going further. I live in the west, so I need to be able to traverse the hills in reasonable fashion!