It will work on all g74sx models, the differences between models are in processor type which will only affect ssdt.aml, it's very important to put the exact ssdt.aml for ur version (mine is 2630QM 2.0 GHz), and one other difference is the VGA card, if u have the BBk-7 from ebay, then u have a GTX 560 2 GB VRAM not 3 GB, all other specs are the same.
Although this post is not full, u'll need blueooth kexts from here
http://www.osx86.net/10-8-mountain-lion/19097-g74sx-tz391v-os-x-10-8-2-install-guide.html and don't use the sound kexts found here also which are (AppleHDA.kext and HDAenabler.kext) use sound kexts from the link i provided which are only (AppleHDA.kext and IOAudiofamily.kext).
One last thing is the Nvidia drivers which are found here
http://www.nvidia.com/object/macosx-304.00.05f02-driver.html
PS. DON'T use the osx.net method, use this thread instead. After this you will a fully functional mountain lion 10.8.2 with working sleep,mic, and bluetooth which are not covered in this thread. Take a deep breath and do exactly what this thread says with the other things i mentioned, if something goes wrong you can always re-install it from the usb (i re-installed it like 10 times to understand everything).
And YES ! it can run final cut and every thing, this laptop is more powerful than any MBR offered from apple.
Happy installing.
