Gear change?

Here is a simple chart, just find the closest gear ratio and tire size, and you'll get the RPM at 65 mph. http://www.quadratec.com/jeep_knowledgebase/article-26.htm In your case you are going from around 2696 RPM to 2872 RPM. That's only about a 6% difference (at any speed). I doubt if you'll notice too much of a difference by doing this.