Hans FWIW; these actuators came highly recommended by a guy whose dealt with them a time or two; 69pace.
http://secure.classichq.com/68-69-RS-HEADLAMP-VACUUM-ACTUATOR--P485C59.aspxI have not switched mine out yet but if and when I do, these will be my choice unless something else come a long that's better. What attracted me to these is they look dead on and they're supposedly;
Tested Individually, and come with a one year warranty. Not sure about the tested individually part but hard to beat the 1yr warranty. One would think if the thing is going to fail it'll darn sure do it before then.
I had some issues with the RS headlights a while back. If you are interested, here's the discussion;
http://www.camaros.org/forum/index.php?topic=8300.0