Just ran 70 mph, I’m one line under 2k, looks like 1900 rpms is my guess. 4:30 gears and 37’s give you a ton of pulling power, and the exhaust brake really comes on strong. I think you’ll be fine with 4:30 gears and 37’s or 40’s. Look at it this way, if you run 4.56 gears you’ll be fine, but if...