Dan, Loren,
I've got a number of those at home. All from Chevrolets. There was a massive GM recall in the late 60s dealing with motor mounts.
The rubber between the engine mount plate and the frame mount would deteriorate and come apart. The side of the engine would
torque upward if the rubber separated and sometimes the throttle would jam. That's what drove the recall.
Instead of replacing motor mounts, GM used various brackets & cables to prevent the engine from lifting on acceleration.
Just pulled them off both mounts on my 66 396 a few weeks ago.
Mark
