I'm presently running 12 bolt/detroit/3:73 rear 10 bolt/3:73's/e-locker front with 33 bfg mud terrains/sm465/205/383/6 inch lift. I am upgrading to 37" IROC radials and am not sure which gears to change to. Presently living in Florida I am not doing much rock crawling just mud and trail stuff and general off roading though the truck was built when I lived in Washinton as a rock/trail rig. I am moving back but I will focus on a 14 bolt/d60 swap the for the rocks. Presently, I am keeping the 12 bolt/10 bolt, I am getting the 37's. I need to know what you guys (and gals) think I should run for gears. I heard something about not being able to use my current detroit on certain gear sets (4:56's and above?) also I am worried about strength of my front and rears if I go to the 4:56's. There is a guy I know here that is running a k-5 with 44's on 10-bolts front and rear with a 450+hp small block (all high rpm power as opposed to my all low end torque) and he has NEVER broke his front/rear ends and he is running lock-rights. Remember I am mostly mud and offroad now with rocks later (no problem with switching, later). I won't go to a gear set that doesn't allow me to use my current detroit. I have the "granny-low" 465 so I was wondering if that would make up for the lack of 4:56's if I went to 4:11's. I respect this forumsknowledge base I would really love some level headed advice. Later.