I have had a fairly insane amount of firewood in my truck before....enough to make the back bumper be about 4" off the ground (truck is stock height) and my tires squat down to about half the normal sidewall height. It swayed back and forth quite a bit.....as well as it rode kind of weird. Steering wasn't that great with most of the weight over the rear axle, and my brake pedal was kind of stiff but the old truck had no problem pulling hills with the wood in the back
Good point on the suspension lockout longhorn man....i never thought of that. I was thining....what about the factory-like set-up with add on leaves. Wouldn't they give the handling, traction, and ride of coils with the load hauling ability of leaves when you load the truck down?