Justin Weiss 
, Jan 11, 2009; 10:29 a.m.
On the new Gitzo quick-release ball heads, like the GH3780QR, can you remove the entire QR system and replace it with something else, like an ordinary, non-QR Gitzo plate, another company's QR system, a vertical bracket for portrait shooting, etc. Or is the Gitzo QR system permanently attached to the ball head?
Thanks!
Joe Allebaugh , Jan 11, 2009; 12:17 p.m.
Justin,
You can view or download an exploded diagram of each Gitzo product (in the format of an Adobe PDF file) from their site - gitzo.com. Go to the Spare Parts area under the main page and enter the model number, such as GH3780QR as above, or a broader descriptions such as "ball head", and follow the links to open each diagram. The GH3780QR model you reference appears to have three small bolts holding the QR assembly to the stem of the ball.
I doubt that you'll find another brand of QR system using a similar three-bolt attachment scheme. If you're after the more standard Arca style attachment system, including an L-plate as a vertical bracket for your camera for portrait, you'll find plenty of references here by searching this forum.
Justin Weiss , Jan 11, 2009; 02:34 p.m.
Thanks for the advice. I checked the pdf's for the QR and non-QR versions of the GH3780 and it looks like they both have the same 3-screw attachment system. So I think I could switch the regular round base for the quick-release assembly.
Moreover, I now see that Gitzo also makes an Arca Swiss adapter (GS5160CDT) so Gitzo QR heads can take Arca Swiss plates.
Edward Ingold 
, Jan 13, 2009; 11:24 a.m.
I know you can adapt an RRS clamp to a Gitzo 1377 center ball head - I've done two of them so far. Call or email RRS for information on the conversion of other heads (http://www.reallyrightstuff.com).
The Gitzo "Arca" adapter is a joke. It is huge with a 4" clamp screw, poorly made (die-cast), and moves around on the head unless you make a bushing to fit around the mounting screw. Notice that the plate which comes with the adapter is the same as for other Arca heads - the size and bevel angle is completely incompatible with Arca clamps (even the Gitzo version). It is shown mounted on a G-1377 head. In fairness, the Gitzo adapter has the proper angles to hold Arca plates securely, and in a pinch will hold the small Gitzo QR plates (less securely).
