Um, you can... I was running GTX 285 tri sli yesterday on a Z77 Fatality Pro which doesn't support tri sli.
Install the Hyper SLI hack for skt 775, use two small flexible bridges and one vey long flex bridge, no problems
Thanks guys, batch no L630A830 (gem 4Ghz + air)
I haven't tried in another chipset yet, I will have to, this result was FSB limited, the cpu had more in it