i need help with my diff gears in my 4 runner
 

hi all im new to this site,,im in trouble,,i think ive done the centre or the axel's in my rear diff in my 1990 4 runner 22r petrol 5 speed manual ,and want to buy another diff but dont know what diff gears are in mine as theres no spot to see what gears its running,,and been told if i get the wrong diff gears it will **** my transfer case......does anyone know what gears the 1990 petrol's run????