Outer Limits 4x4 Board

I am taking my Second air beadlocks that I bought second hand (does that make them Fourth airs ) a year ago down to the tyre place tomorow for fitting.
I have looked here http://www.secondair.com/howitworks.htm for some basic instructions.
I had the tyre shop having a look of terror on their face for a while today as they had never seen anything like them before
Is there any more tips or important info that I need to know?
I know that they recomend a bit more pressure in the tubes now.

This bit had me scratching my head a bit

second air website wrote:Fit the special valve to the original valve hole with the slot parallel with rim edge and tighten.

I would have thought that having the slot at 90 degrees to the rim edge would let the air through better?
Paul.

You need to have them parralel so the air is directed to the edges of the little flap that fits between the valve and the beadlock tube. Make sure you use heaps of talcum powder in between the tube and the liner and be extra careful to keep it all as clean as possible and make sure there aren't any burs on the new holes you drill. Make sure that when you get the second bead on that you take your time and check that it all lines up properly and if you are fitting to new tires that you are very careful when you pump it all up for the first time so you don't pinch the tube.