I added a total of 6" to my 03 RX1 2" powermadd pivot riser and 4" riser block. Had to get the 05 Mountain cables (brake hose, throttle, parking brake, and choke). After I took the stock ones out I compared the lengths on each and found that the choke cables were the exact same length so don't think you need that one. The rest are slightly longer and still required rerouting for the parking brake cable to make it work with the 6" rise. At 4" I would say you still need the longer cables. Rerouting might work but it would be super tight and likely to cause problems by engaging the cables if your skis are turned all the way left or right. Minus the choke cable, it runs about $90 for all of them. Here is the nomenclature for all 4 of the 05 Mountain cables:
8FW-26311-00-00 Throttle cable
8FW-26330-00-00 Choke cable
8FW-25872-00-00 Brake line
8FK-26351-00-00 Parking Brake Cable
BTW, while you're at it, upgrade to the apex or nytro seat. I did that as well and man, what a complete difference! I hated this sled before. Seated too low and bent over too far when standing. Now it rides like a dream. I can ride much longer and more aggressively. Below is a pic of the final product.
Good luck!