Put some good shocks on it. If your tires are properly balanced with good equipment, that isn't the problem. If you're driving empty, make sure you're at empty pressures. Mine are 50f and 40r according to the door. Some have said their newer trucks recommend full load tire pressures when empty because they aren't publishing light loading pressures anymore in the door. If you're running 70+ psi empty, your truck is going to ride horribly no matter what suspension you're running. The tires are your suspension for high frequency vibration; if they're hard as a rock your ride will be, too.