[knomadd]

I had a 3.5/5 before going with air and would notice the rear would hit the cut down bump stops on a large bump, but nothing too bad (no notch). I'd imagine you'd be hitting the bump stops pretty regular with a 6" rear drop. But that will also depend on the company you buy the springs from. Some companies will advertise a drop based on out-of-the-box height while others will advertise their drop based on a settled suspension which can take months to get there. I don't know which companies drop is out-of-the-box vs. settled though, so good luck.

I wouldn't imagine a long bed would make much difference on the drop, but I doubt a 3" or even a 4" drop would be a problem with bump stops.