i can't imagine you would. it will require a bit of fabrication to install, but as long as the downstream O2 sensors are installed correctly, there shouldn't be a problem. I haven't done this conversion at my shop, but it should be problem free. keep in mind the exhaust on a 55 is a true duel exhaust and the piping diameters/routing are slightly different. inspect the system closely to see how much of a hassle it would be. you may end up just using the mufflers and having an axhaust shop custom bend some piping.