95-RA

Ive recently bought a 95 ra and theres a tooth off on the front diff. Im struggling to find another box to match. My plan was to remove the box and put in a temp till i get the original fixed. What other gearboxes WILL fit? I need someone who has knowledge of ra's and can give me a definative answer as im not a specialist. Changing the box and rear diff may be an option if its cheap enough, but I dont want to buy somthing thats not going to fit. Any sensible options........