3.21s are the default option, so that is probably it. Do a few searches on the forum for 35s and 3.21s and you will see mixed answers. Some people are running it just fine, others have issues. A few people say they don't have the issues switching between 7 and 8 on the highway. I'm on the fence on the subject too as I want to do a 6" lift with 35s but I have the 3.21s. Luckily I have some time to decide what I want to do. You can always disable 8th gear with the gear limit selector on the steering wheel if you find it annoying or problematic.By standard I mean what would typically come on a truck