you could switch to the 4.22 or 4.27 axle ratio's depending on what axles your ride has it will determine which of the two and either ratio can be had at a junkyard out of a mitsu pickup in oz. here in the us you can get the 4.27's out of a blister fender montero and even some montero sports. 4.22's out of mitsu v6 pickup's. engine grut and depending on what type of wheeling you do you may end up needing to regear your transfer case which isn't a bad idea anyway.

89 2 dr turbo diesel
89/88 "Backwoods sas"