Joe
If you can cruise @ those RPM'S you will will be OK I think.
My L78 Camaro, M22 with 4.10's and F70 14 tires is at 3800 R's at 62 MPH.
Now I sure would not take off on a power tour, but I sure as heck ain't given up those 4.10's

You need to do this

at times
I do make some 20 to 40 mile trips on the I state's and 60 seems to be my comfort zone. Good luck.
Mike