I think there's a few things that are generally helpful for drifting
- Adjustable diff if the car has no limited slip diff already
- Zero out the rear toe that every car has by default (need full suspension to adjust this)
- leave drivetrain components stock (flywheel, driveshaft, and depending on power, the clutch too)
Adjustable diff and full suspension can be left at default settings after installation, except for the rear toe.
My opinion is that the rear toe-in built into every car is detrimental for drifting. It causes too much rotation while drifting, as well as too much inward movement. Zero out the rear toe for longer, more predictable drifts. Set to 0.20 toe OUT for additional effect but the car will become more unstable in straightaways.
Lightened drivetrain components can cause too much rising/dropping in the revs during a drift... leaving them stock can smooth out your controller inputs and keep the revs more steady.