Rage 4 for the X3 and Defender and secondary spring upgrade. If you do not already have anything changed in your secondary or have the STM secondary, you will need the spring with the Rage 4 at a minimum.
The idea behind the Rage 4 vs a Rage 3 is having more mass to control shiftout for higher HP applications. The more HP you make, the more flyweight mass it takes to control shiftout. If you are less than 200rwhp I would recommend the Rage 3 with 60gr base weights.
We will set the calibration based on the details provided to take the guesswork out for you.