Dang! 3.07 is steep! I have an Sm420 in my 3/4 ton with 4.11s. Tranny grinds into 4th, but haven't had issues yet...and I've lead footed 9,500 pounds. lol I'm going to do the road ranger setup as I love the fact of being able to split gears when I need to, and get an od out of it.