I had the need to rebuild a motor on my former 1978 Lincoln Continental Mk V Pucci and that motor had three triangular plastic pieces which were replaced with urethane ones. My mechanic said the idea was that if the motor was over stressed the plastic pieces broke, preventing the motor from burning out, preserving the motor in any case.
Before purchasing new ones you could try stripping, cleaning and rebuilding yours, then again the Cardone ones may save time and hassle.
It's just that considering how old our cars are, things need rebuilding, gee mine (73) is 44 - amazing it lasted so long in great condition. Going to get some Steppenwolf (Easy Rider Theme) and cruise the Wisconsin freeways in October/Nov.