You were having vibration problems with the motor and trans a few years ago. Wouldn't be suprised if the drivetrain (trans/rear) vibrations had an impact on your failure.
Sometimes, and my conviction is that if you push a concern long enough, something more expensive will bite you.
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1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.