Factory driver and designer Billy Easton posted some tips on the new parts – The more caster you run, the more on throttle steering you have, less through corner steering. Basically, they push more going into the turn, but have more on corner exit. If you have a corner entry oversteer you can use more caster to reduce that and smooth out the steering. the bi product still though is more corner exit steering. In some cases, they can make you faster due to more corner speed, but sometimes they can make you slower cause its understeering, it really depends on the track
At first I ran 16 deg blocks, which seem to help in rougher tracks, but they have might push a little too much on tight tracks. The 14 degree blocks seemed to work really well as the best balance between steering and handling.
The parts come in sets of left and right C-hubs including matching hardware and are black anodized and laser engraved. Generally more caster give less steering into a corner but more coming out of a turn. The new parts help to find the best setup for your given track condition or driving style.