Look at this on eBay http://www.ebay.com/itm/282184991300
Those are not recommended for high speed boarding. They are too unstable.
True, though I have one as front truck on my 20mph max board and it super fun carver board.
I had an Evolve for awhile that had those. Worked fine if you kept your top speed under 15mph. Once you get past that, you need harder bushings to keep them stable and you start to lose your turning radius. Nice for carving on a regular board or if you keep your speed down.
I used to have a set. Never took them over 10 mph.