The 2020 Option Kit includes C-Hubs and Steering Knuckles with #2 KPI. This is a large amount of KPI that makes the car have a "pillow ball" feel. It has smooth initial steering, stability on power in bumps and sweepers, along with great on power steering. It is definitely faster for drivers that enjoy driving on power. For drivers that prefer a more point and shoot driving style, and turning off power, the zero KPI may be better.
The rear hubs are updated, with the short middle hole being the same as the old low long hole. So there is an additional low row for loose tracks, and also a longer link location, to add grip for the large KPI, which can be aggressive exiting corners on power, causing a loss of rear grip. The rear hubs also add the option of using long rear CVDs with the joint inside the inner bearing. These smooth out the traction levels, being specially good on difficult tracks with inconsistent grip levels. You can also use the included inner bushing that fits the stock bearing and universal drive shaft.
This is not an upgrade kit, but an option kit. It is very different to the standard parts, and different conditions will require, and different drivers will prefer either one of these. Enjoy testing and learning about the new KPI hubs/knuckles, and rear hubs with the CVDs, and new link locations! We recommend you try the #2 steering plates (JQB0382B) with these parts, and mount the link in the middle of the ackermann plate.