Most likely was and yet Porsche did pretty well with the swing arms. GM couldn't have 140,000 mile air cooled engines in all their divisions ... Why what would the sales managers say ?
I know this from first hand experience. The left motor mount would fail and rock the motor to the right but this would only happen under hard acceleration then drop back into place once the ignition was shut off or the clutch pushed in. The early fix was to chain the motor down (350 ci ) and the proper recall fix was to change mounts to 396 ci mounts.
my first car, a 65 impala had the recall "fix" which amounted to a short steel cable with a loop on both ends that would keep the engine from lifting if the rubber mount broke.
This thread is well off the rails already so I’ll proceed with my question. What caused the problem with the Chevy side mounts, a system in use since 1958? Was there a design change, or maybe the rubber composition was modified, I don’t recall a reason being given.