TheBlueMaxII

Does anybody know if you can effectively upgrade the GTX 770m in a Toshiba Qosmio X-75 for a GTX 780m? The Qosmio uses MXM 3.0B for its dedicated graphics, so physically a 780m should fit, but I was just wondering if anyone has tried it or would know how to find out if it would work. I'd prefer not to waste the $180ish on a 780m if it isn't gonna work. I've looked around for information about this, but so far I haven't found any concrete evidence.