I have just purchased a Torsen biased diff from gurumotorsport, and have had the car up on the hoist removed the existing diff centre only to find that the opinion and crown are absolutely stuffed. I've called around the wreckers and only been able to come up with one price so far that is excessive i feel. $395 for a 1980 centre.

I was wondering if there are any alternative centres that could be used out of other mazdas of that era? I want to keep the standard ratio of 3.9:1.

 

thats very expensive. i just picked up a full diff center for a 79 for $120.
if u lived in melb i got busted center with a good crown still on it.

 

some miata diffs (and gears) will fit.. but that will not realy save you any money.. you are just going to have to bite the bullet an buy a new one, or grab one out of the junk yard..

 

umm I see your in australia so no confusion over models

its a 1980 model? so it runs the small axles.. oops it doesnt matter as you now have the guru torsen centre

to my knowledge, pretty much all early RX sized diffs will fit, 929 (RX-4 shape) capellas etc. but what I have got in my 79 is an E1600 diff centre, it has the 4.44 ratio in it, and it cost me under $50 basically all early diffs which started behind a rotor or a 1600 or bigger psiton should fit, but the ratios may vary.

good luck in your hunt. although the E series 4.44 centre is very nice in my car, I like the extra takeoff.