Tall gears and 4-speeds

Well the newer dodge (automatics) are a double overdrive. On my '12 truck, 4th Is direct 1:1, 5th and 6th are both OD. 6th is actually pretty steep, seems like (if I remember right) are a .60-something ratio. So a low .7's probably won't be too bad for final drive on something like yours. How often are you thinking you'd be able to utilize top gear in your Normal drive mode?
When I had my wrangler with a 4.0 inline 6, a NV3500 and 3.07s in the diffs I couldn't use 5th as much as I'd have liked without lugging.