any posi out of a 8" equiped ford. mostly found in mustang 2s. the way to check if its a posi is to turn the wheel on one side and one of three things will happen, 1. the other tire will turn the oppisite direction. this is a open non posi diff. you dont want it 2. the tire wont turn. this should be a posi. it doesnt turn because the trans. i in park or in gear. put the trans into nutrual. now you should get the third results. 3. the other tire will turn the same direction. this is most likely a posi. confirm it by puting the trans into park or nutrual and you should get the results listed in #2.
They made the Mustang 2 between 74-78 I believe. The fox body Mustangs 79-93 had coil springs, I would imagine one would work if you can cut and weld.
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