If you wanted to you could just place a brick onto the throttle and let it hit the governor and run it there all day long with no problems.
If I am unloaded I'll run my truck at 80mph all day long and not even give it a second thought. Loaded I'll keep it around 70.
With your 35's have you re-calibrated your speedometer for them?
As for swapping gears if I would do it I'd go to 3:55's. 3:73 is so close to 4:10 that I doubt that you would notice much difference. Also where you tow or haul things could help in your decision. I do most of my driving in Colorado with trips to Utah, Arizona, Wyoming and Idaho so I get into a lot of hills.
I have not calibrated my speedo. I know it’s about 4 or 5 mph off from about 30mph+ according to GPS and speed traps. It may try closer to 10 mph at interstate speeds. All my towing is gonna be done on mostly flat ground with a very minimal inclines. It was my understanding that with a zf5 the gear ratio is reslly gonna be most noticeable in OD/5 that being because of the very close gearing in the trans it self