My 74 Mustang II with a four cylinder did not have an 8 inch rear axle but had a 7.5. This axle does not have the third member housing that can be removed as a unit but instead had a rearend cover that had to be removed for access to the differential. I think it was the same rearend offered in Pintos. Since I put in a V8, I changed axle housing to an 8 inch from a 75 to 78 Mustang II. 74 was the first year for the Mustang II and was only offered in the US with a four or six cylinder engines. The six cylinder might have had an 8 inch rear axle but I am not sure.