Easy wrote:
You're not fat and you say that you're in good shape, so I agree with the other poster that said that you can probably run a 4:30 marathon right now. It wouldn't be smart or healthy, but having your marathon training be 9mpw isn't gonna make much of a difference.
Yep, pretty much this. You can probably get it done with the training background you cite, but the reason it's not a very good idea is you run a risk of putting yourself out of action for your normal training or, more likely, returning to your usual training and injuring yourself at some point in the few weeks after the marathon.
This injury is a greater risk for you than injuring yourself in the marathon proper. It'd be wise to carefully plan your return to your usual activities, and err on the side of caution for a few weeks