Furman FIRST training schedule?

I glanced at the schedule before, and the workouts looked pretty intense. At the time I was working out with a heart rate monitor system where I was supposed to keep my HR low. But I wasn’t getting any faster, and my aerobic fitness didn’t seem to be as good as it had been when I was doing easy/hard workouts. So I switched, and my running improved.
I am currently using a schedule that I created myself that it modified from a schedule in the 4 Months To A 4 Hour Marathon. I previously used the 4:30 schedule from the book and ran a 4:21 marathon. So I took the 4:00 schedule and tweaked it into a 3:30 schedule.
But now I am looking at the Furman FIRST training schedule. It is similar to my schedule, but drops the easy runs. The other runs also look harder. I ordered the book Runner’s World Run Less, Run Faster: Become a Faster, Stronger Runner with the Revolutionary FIRST Training Program. That supposedly contains schedules for all the Boston Qualifying times.
RIght now, I am debating jumping from my home-made schedule into the FIRST schedule with only 7 weeks to go. LOL! I jumped into the 4 Months To A 4 Hour Marathon with about as much time left, and it worked out pretty well.
I am not expecting to run a 3:30 marathon in September, but a sub hour marathon would be awesome!