The domestic market gives lift at the valve stems and note down the rocker arm ratios. There's also much more publicized information, like lobe separate, centerline, and duration at advertised and measured 0.050". The reason a specific rocker arm size is noted is because people change rocker arms and ratios. It's a simple wear item that can also be used to extract more performance by increasing lift without changing the cam.

For an example:
http://www.compcams.com/Technical/Cu...ML/128-169.asp . There is even more detailed information out there then what is listed. You can get the full specs by contacting the manufacturer, or some other places which may list the full cam card.

I always wonder what is up with the import market, it's so strange. You don't know what's real or not. There's so much hype, and for someone who comes from the domestic market, it really plays up to the ricer stereotype. No offense intended.