My advice would be to just run 35s but then again I'm old...
Anyway 35s seem to be the line between having to spend a whole lot more money on a front end vs. just a basic upgraded birf & hi-steer setup. I don't get on slick rock but we have done a bunch of rock crawl comps over the years and this theory comes from what we have seen there.
I actually have a buddy who has run 37s and bigger for years and he is going back to 35s because he and I can always take the same lines and he is looking for max dependability.