All the stuff that was approved in Sport Category, plus in Tuner Category, you can have mechanical Limited Slip Differentials (LSD), and replace final drive ring and pinions with alternate parts as long as the final drive ratio isn't changed from OE.

You can also use an aftermarket pressure plate and clutch disk as long as they are both the same diameter and design as stock; so no multi-puck clutches unless your car came with it from the factory. You can replace the flywheel as long as the diameter and material are the same, so you can't put an aluminum flywheel in place of a steel one.

Differential bushings and transmission mounts can now be replaced, as long as they are the same material as stock (solid metal is a no-no).