Thanks for the replies!
I dont think its the exhaust. I had new mufflers put on after I bought the truck and while I wont say that the exhaust system is rattle free, I know it isnt loose enough to make a noise this loud
Will I be able to move the trailing arms enough to tell if the bushings are bad? Or is it something I'll be able to see? I wonder if I should jack up the frame so the rear end is hanging free and see if I can locate it that way