Maybe they broke a mount previously? Check the fan shroud for any scraping by the fan.
Wanted to restrict engine motion for racing?
Saw it somewhere and just had to have one?
Quite common in the sixties and seventies. As said, high torque on the standard mounts broke them easily. Turnbolts and chains were the common cure. A chain allowed for less engine vibration, yet still allowed restraint of the engine when accelerating .