My friend has a 06 3500 Crew Cab dually 4x4, it is bonestock except for the 19.5" wheels and he is looking to put a cat-back exhaust on his truck, he has no plans of running a programmer, just wants to make a mellow exhaust sound and maybe do something with the intake. He was thinking something like an MBRP 5" catback but will he loose his spare tire with this setup??? Any thoughts or suggestions would be greatly appreciated. Also this truck is primarily used to tow his 20k gooseneck or 14k fifthwheel camper. Thanks in advance for your help.