I have A buddy in Virgina with the 2.5 and 33s <img src="/forums/images/graemlins/rolleyes.gif" alt="" />. We used to go up in the mountains and all i have to say is I wouldn't do it. He was almost always in 3rd or 4th gear in the hills, he also had stock gearing i don't know your situation. But it was a <img src="/forums/images/graemlins/oink.gif" alt="" />. Id do gearing before you do tire go with 4.56s or something along those lines. And im sure the hills in Colorado are much worse then the ones in Southern Virginia.