Other options wrote:
What have you been doing so far? Mileage? Workouts? You don't want to overdo it and go into the race fatigued. That will only make you do worse. I would focus on quality workouts over increased mileage if you have 6 weeks. 4 mile tempos, 800-2k repeats at 5:30 pace, and 200-400 reps faster than race pace. If you can do those every week with filler easy mileage it will be your best bet. Don't overdo the workouts either but you will get more from this than 75 mile weeks for sure.
Thanks for the input. I've only been doing easy mileage since about February. Before that I hadn't run in several months.