I agree with Burnt, my dad had a mandrel bent, stainless, dual, cat-back exhaust, complete with stainless Magnaflow mufflers and stainless tips, built and installed on his 02 Dakota with a 4.7 V8/Auto for $502.00 out the door at a local exhaust shop. They bent the pipes so they exit just behind the rear wheel at an angle. It looks great, sounds very agressive and I think it definitley helped in the HP department.
Joe