I agree with Lynn, and would add that you ought to consider your total drive line vs intended use when you're looking at your rear gear ratio. Picking out a set of gears is one of the critical decisions you'll make for long term reliability, performance and efficiency. I don't see where you've mentioned what transmission you're running, and the other key component is your rear tire diameter measured as accurately as possible - best way is to inflate the tires to your normal pressure, chalk a line on one, then roll to put the line at dead bottom and mark a line on the pavement. Roll one revolution, stopping w/line dead bottom and measure between the lines on the ground. Divide by PI and you've got your true OD. An inch in OD makes a difference. Once you get that dyno run it will also show you the lowest rpm where you're getting up on your torque curve. Pick your cruise rpm, and set your rear gear ratio accordingly.