picked up the stock style one today from O'Reilly's. It looks great, and if it is made anything like the original then I am not worried much at all if it will fail. My old one made it over 40 years, it was definitely original based on all the rust and amount of fusing of the parts onto each other and the steering box. I'm glad I am replacing it.

I decided to not go with the poly because of the lack of reinforcement. The rubber one has the fiber weave inside of it that will fight against the amount of twisting this part does. I would think that a poly one wouldn't be as forgiving, those things are much harder. Plus, the rubber one was like 8 or 9 bucks and found at a local store, whereas the poly one would probably have to be ordered and costs $27 and up plus shipping.

 

Poly doesn't need reinforcement because it doesn't tear as easily as rubber does. Without the fiber weave the rubber ones would tear very quickly. And I was actually a bit surprised with mine, the poly seems to absorb vibration pretty well.

 

Trouble is, poly, when it get old, or very cold, will shatter like glass. I've seen it. Not a pleasant thing to see on a steering coupler.