Outer Limits 4x4 Board

Hi all;

I live in Chile; I have a 1992 SWB nissan Patrol GQ with rear drum brakes and 4.11 gears; to which I want to swap 3.5:1 gears from a later GU model;
I know that for the front axle it will be ok but will this new ring and pinion fit my rear H233B axle with drum brakes?.

The other possibility is buying a ARB for my back diff and fitting that with the 3.5 gears, will that work maybe ?

Thank you

PS: by the way if any of you has some extra 3.5 gears in good shape I'll be glad to buy them from you

Is the GU a high-pinion front diff like the GQ? If not, you won't be able to swap the gears between the high and low pinion units.