Overdrive Options

You must consider the rear gear you are currently running?

Ex: 3.21 with the 200R4's .67 od gives you a 2.15 in 4th. Might be a little lazy even at highway speeds.

With the above ^^^^^^^^^and a 26" tire, you'd be about 1700 @ 60mph.
1700 at 70mph is and even better number in my opinion.