Gear oil for a Subaru

I'm completely sold on RedLine shockproof gear oil for the gear box but how about the rear diff?

I'm not 100% sure it's the oil best suited for that application so I figured I'd ask here. If I remember correctly it currently has Amsoil Synthetic 75/90 in the gearbox and Mobil 1 Synthetic 75/90 in the rear diff. I put it in 7 or 8 years ago,(before selling it 5 years ago, then buying it back with a locked up engine 3 years ago) and I know the people who bought it didn't change it, hell they didn't even check the engine oil.

This will be going in my Brighton and it will see Solo2, Rallycross and ham-fisted abuse pretty much daily so it needs all the help it can get.

My WRX got shockproof in the gearbox and redline 75w90 in the diff. No problems over 80k miles of drag passes, track days and the like. You can also search "uncle scottys cocktail" on nasioc for a well-recommended blend of a bunch of different fluids. Never tried, it, as I never had a problem with the straight redline stuff.