Welcome Scott:
One area to think of is the 3/4 ton rear axle. It will have a 4.57 ratio (5.10 was offered as an option). Your top speed will be about 50MPH. You can easily get a 3.55 gear set for the 1/2 ton, but I don't think anyone makes replacement gears for the 3/4 ton rear axle. I ended up getting a Gear Vendors overdrive for mine, which works great but is expensive. It is kind of neat to have 7 speeds, but hardly necessary.
