Let me ease your mind. My first F 350 SRW crew cab 4x4 was in 1996. It had 355 gears and when I installed 35" tires it would not get out of its own way. Had to trade the tires in for 33's. At that time stock tires were 31"I am special ordering an F350 6.7L 8' bed 4x4 single rear wheel for towing a 35' 15k lb toy hauler.
I am shocked to see that you must switch to dual rear wheel to get gears lower than 3.55.
I plan to only install a leveling kit and 34 to 35" Toyos on either 18 or 20" wheels, but 3.55 seems light.
I would be comfortable with 3.73, but had planned to push for 4.10.
Today the trucks have twice the power and are geared for near stock 35" tires from the factory. I just installed 35" Toyo's and I am dead on with the speedo and GPS with 355 gears. I wanted 373 but not necessary. Back in the day you needed 410 gears. You could get in 1996 a F 250 2 wheel drive Powerstroke with 410 gears. Not anymore, and not needed. If you stick with 35" and 355 gears you will be fine.