My car is very loud on bumpy streets. What do I look for?

Thanks everyone. First off..I changed everything. All bushings and parts. I used poly bushing in the upper control arms but it was making the noises before that. The steering link is pretty close to the exhaust pipes but I dont see any damage on the pipes. I reckon there would be. Has disc brakes already and holding the brakes improve it. And no sway bar installed.
Could you expand on that torsion bar comment? My build sheet says I have 891 and 890 bars. My car has the 5.3L motor. I have a hard time understanding torsion bars. They say stiffer bars give harsher ride..but isnt that what you need to absord potholes and things? A soft torsion bar would just bounce the car around and bottom things out no?
Also in the spring my tires were very low on air and the ride was much more quiet. It got louder after I filled to specs. That might be a clue no?