you will need to break the dial feet and use double stick dots in order to make it stay in place. otherwise it should fit. Because of the large luminous markers, you might have a problem with the 6309 chapter ring though (don't quote me on this). Maybe someone else knows better.
The Monster dial will show the holes where the original chapter ring attached to the dial. There are eight of them. They're not huge, but they are noticeable and the fact that they're assymetrical may be bothersome. Look closely at pics of 007 mods with Monster dials and you can see these little holes on the dial near the chapter ring.
Also, I think the date window on a 7S26 dial is just a tiny bit off (to the left or right, can't remember which) compared to the 6309 dial. This might not make a noticeable difference, however.
Update: I just tested this fit using stuff I have lying around... it seems to work fine. The stock 6309 chapter ring does seem to provide clearance for the Monster dial's lume markers.
The date window on the 6309 dial is a tiny bit closer to the center of the watch than the 7S26. Maybe 1 mm or so. I'm not sure how this difference would affect the look... probably fine, but I can't test that part to be sure.