Which oil for new gears with ARB locker

Guys. I finished the brake-in of my new 4.56 USA standard gears on my 8.25 chrysler (300km) it has an ARB locker, I used 75-140w syntetyc oil for the brake - in.
Shall I change to a less oil weight or continue with the 75-140w and shall I add an additive oil ?
If yes wich one and how much over the regular oil capacity please.
Thank you

I used 75-140 in my ARB 8.25 axle. No additives required.

The ARB doesn't care. I would stay with 75-140w

Fwiw Currie recommends non-synthetic gear oil when they setup an axle.
They use torco 85-140. That's what I run.

MyaXJ is open/open, but I run amsoil severe gear 75-110 front and rear. For simplicity. If your rear axle requires the same fluid as what you are using in the front. Keep it simple and use the same.