With 26" wheels and thin tires, there's not going to be much ride quality you can feasibly gain, especially on a truck with rear leafs and a solid axle. Cadillac it will not be, no matter what you do. That being said, the Fox 2.0s will likely ride a bit smoother and be more controllable than your stock coilover assemblies and rear shocks. You will need to adjust the Fox coilovers down to a 0" ride height, since they come out of the box preset at 2" of ride height.