I occasionally get a load of gravel for my driveway and they usually put in about 1/2 yard (at least that is what they tell me!), the bed drops a lot, but does not get too close to the tires. That is as far as I like to go. Then I drive the back roads home to avoid traffic and keep the speed below 40. I am also still running the original springs, so that can make a difference too for you if yours are in better shape.
Lee.
