Oh, and Ron O....an answer to your original question:
I tend to run between 70 and 80 on turnpikes (if you're on I95 in the South and not doing at least 80, you get run over).
Running 16 inch rims and I think I have about 24.5" diameter on the outside of the tires (at least it sounds familiar for a 225R16X50).
The tach usually runs between 3,250 (about 68) and 4K (about 78), and most often between 3,500 and 4K (sometimes blipping to 4,200 if I'm on the New Hampshire Turnpike on a Friday afternoon and just trying to keep up with traffic).
On highways it seems to like running above 3,250 but with the external cooler it never goes above 200F no matter what, unless I stop for a light or something and then climbs to 205F and stops until I move again and then returns to 200. All checked with a Dipstick thermometer.
This help?
gn