I drive mostly around town on 3.25 and 25 1/2" tires and the rpms get old. To me it stops feeling like crusing and makes me feel like I'm working the car all the time. I think we are so used to overdrives anything over 2000 rpm is for accelerating.
That's about what I have 3000 rpm is around 69 mph 3500 80 mph . I'm thinking hard about an 0/D where 2400 will be good for 70 mph , even with 3.55 or 3.73 70 mph would be 2600 - 2700