This is what I do on both my Open B combat planes and my Q-25 pylon racers. I use this aftermarket OS needlevalve:


http://www3.towerhobbies.com/cgi-bin...&I=LXCR48&P=ML

And then I attach it to the airplane using a large landing gear strap. One end holds the assembly and the other hole is attached to an engine lug. If you need a 90 deg angle on the attachment, you can use a control horn.

http://www3.towerhobbies.com/cgi-bin...I=LXDMG5&P=ML#

So far I have had excellent success with this method.