I've been searching for a riving knife retrofit for my old Powermatic 66, and as far as I can tell it doesn't exist. Most of what I've read suggest that it isn't possible to make a riving knife that attaches to the existing arbor, allowing it to rise and fall with the blade.

It looks like Biesemeyer used to make a splitter, but it has been discontinued. The only option that I can find at this point is SharkGuard's splitter. Does anyone have any experience with this system? Is there something obvious that I'm missing? The last few times I've made long rip cuts on my TS, the stock has begun to pull to the left (away from the fence, in the direction of the blade) after passing through the blade, which is making me increasingly nervous about kickback.

I realize this may be a niche type of question, but I would love info from people more experienced than myself. Hopefully there is an option that I'm overlooking. Thanks.