These
Auto Calculators and
Marlin's Transmission Gear chart might give you some more info.
3k isn't high for freeway speeds, that is where both my 3.0 and 22re rigs run at 70. At that rpm the emgine is just off its power band, giving you just enough power to maintain speed as well as allowing to to pass w/o having to down shift. Even at 70 you would only be turning about 3200rpm's, which still wouldn't be an issue. It might cut into your highway mpg's until you swap to 35's, but you should make up for it in higher city mpg's.
