Mine is just a 4' lift and 33' tires. I think a go cart goes faster on the highway.
I bought mine about 2 hours away and drove her back on the highway, scared to death because my previous jeep was stock. I knew I wanted a big girl jeep, but would have rather not been initiated immediately on the highway until I got the feel of it.
I did fine, obviously. Now, I think nothing of it. I do a lot of highway driving and have learned where to downshift without even thinking. Otherwise, I would get run over by the old blue-hair ladies on the road.
A friend of mine called my cell while I was on the highway with the top off, and screamed at me for doing that. My response to her was, "like you really think that canvas is going to save my life if I flip?!?!" She sat there a moment and then said, "okay, I am blonde."
You will be fine. Just take your time and don't try to be a show-off until you are comfortable with her. Post pics!!!