You can order these from ARP/ Summit/ Jegs/ etc. It's cheaper and you get 5 bolts in the pack.

16mm PN: 671-1017
25mm PN: 671-1002

 

I remember reading the about the Sumo Racing R34 here in the UK that made >1000bhp when i was sub 20 and it had fluid balancing damper back then from some specialist.
The idea seemed great but i have never seen another one mentioned since then.
So it must just be for the motorsport folk.

I wouldn't mind one when Phoebe needs a new heart and the price isn't that bad.

 

Fluidampr used to be used in F1 a lot, I'm not sure what they use currently. I like the idea of a non-tuned damper especially if you are modifying the engine from stock, eg with a lightened crank, rods, pistons etc. I had a look at them a couple of years ago and even found one that could easily be modified to fit on a BP (I think a VW one from memory) but decided it was too much effort and risk.