i would go with the smaller rim size if you will be off-roading. you probably know that you need more sidewall for those conditions. just look to the military H1. id also suggest not going more than the 36" since the proportion of tire to truck starts to look odd. your V8 (with the lift) can handle the 36's no problem. as far as width. i agree on the wider tire as well. it offsets the added height of the lift. post some pics after you decide?

 

Still for sale gents!

 

Would love to take you up on this offer if I was closer.. Montgomery, AL..

 

If you where in Houston, I would try to beat it out of you. I'm waiting on Rancho to have another $500. gift card sale with buying a kit and shock package. I talk to a rep, said most likey, Rancho will be doing it again near Christmas. Think it will be easier to buy a kit than do a swap but would be open to it if; i like I said; you were closer.