differential gear for ratio 373

[powel]

hi ! i want to buy a pignon and the 3 bearings i need to rebuild by differential whit new ratio. it was original from body e30 engine 1.8l twincan . and i try to find new gear for differential. i am from montreal, quebec, and i cannot find any part for my car here. normaly i buy my performance part from the internet but now i am stuck. i cant find the pignon i need and the bearing . anyone know where i can buy the parts i need?

thx alote !