you never know the trouble you seen when working with an old car---when you dont know the full history---that rear may not be an 8.75---unless a newer than 57 rear end was tossed in---mopar had a similar rear end used from about 1931 to 1956----looks like a 8.75 but is just a little smaller---dont know what it was called---probably a cuss word--or a spicer....