RPM's

[70SS454]

My Chevelle is a factory LS-5 454 and muncie-22 4speed. I know cars were different back in the day, but my chevelle tach reads about 2800 rpm's when cruising at 65. I know it has to do with the gears and all that.
However, it seems pretty high to cruise any distance at that constant 2800 rpm.
What kind of rpm do you guys turn on the highway??