What's your actual O.D. on your current tires? I don't think you're too far from 35s now. I was on the lot measuring some stock tires for the same reason.
Taking delivery of 2020 2500HD in a few weeks. I have ordered a Leer cap as well as a Truck Vault drawer system and a Cargo Glide. Recently retired,headed to see the USA. I thought these items would be a good start. I am considering a dual exhaust,and hoping someone will produce a cold air intake kit using the fake hood scoop . I have the 6.6 gasser.