I get 14,510 on my 8800GT @ 726/1260
http://homepage.ntlworld.com/stonedofmoo/CPU/3DMark06.jpg
Your scores look spot on for a mildly overclocked GT
Assuming your temps are not at full load, 59C, hmm. Dunno what your cooler is, but at what is probably ~1.35v vcore, your temps shouldn't be that high after running 3D mark, where the temps plummet. In theory that clock can easily get to 3.6ghz.
To get your clock i need 1.47v heh.