Sorry about the slow response, been busy on property up north for spring cleanup!!
Haven't really done much to the EX, biggest and best was 4.30 axles!! Found a frt & rear (non-slip) matchers with slightly less miles than orig 3.73s. For the V10, it is a great change!! Can handle almost any mountain pass and altitude out west. Mucho better. I have done the Y pipe modification to the V10, not something can do to a 6.0!! Air bags and some rear spring mods. Not much else!! Have 152K on now, and still feels new. Pulls our 34 footer real good, but not a new diesel!! Can't add much else, but also don't know how your 6.0 will do with a large ORV. Should be equal or better than ours on some levels. Would gear ratio help??? Maybe, but the 6.0 doesn't rev (or need to!) like a gasser!!
I'll try to answer any other questions if you have any!! Let me know when you head out here, and where are you heading out from!!??