For the most part my truck is perfect for what I do.

I went to Reno Nevada today through Sacramento on Hwy 80.
On the way there my truck was or seemed doggie. 60 mph in one place in 4th gear pedal on the floor.
But on the return, about 15 miles out of Reno it ran very well. 70-75mph all the way home.

I want a truck that will pull it at 70 to 75mph both ways with out putting the peddle on the floor.

Must have good low end power and chug along good at 1000rpm or lower, over most terrain in low 4 wheel drive.
This is because of ground speed.
A better ride would be okay also.

What do you suggest?