I wonder who has tested a prop shaft on a 1000hp Sy/Ty to make such a claim.
I had a local guy build my shaft. He told me it would be impossible to break. Now i'm not saying thats true, but it is awfully beefy.
It is a chromoly shaft with a slip joint and a single large joint at each end. The shaft was built with racing in mind, so it does have a slight vibration at some high speeds. It's bearly noticeable, but it is there.
While my truck doesn't quite make 1000hp, it is up there. An entire summer of kicking the crap outta it and several trips to the trap and all seems good.
Tony