This is true about perf. mods, but have you noticed it is reversed for things like suspension. My brother has a new GMC Duramax, (which is a nice rig I must say), but you would not believe what he had to go through to get some bigger meats on his truck. They tweaked it up 4", and still had to cut the front bumper and remove his mud flaps.
I understood that it was to put 285's like I have on mine, but the other day we had the rigs side by side and his tires are 1-1/2" shorter than mine still. I did not have to do anything to mine to fit these tires, and that included Rachels Excursion. I sure like our suspensions better.
Barrett