advice about goal marathon pace (Read 322 times)

Well, here's the story. I've been using the FIRST plan for the past 15 weeks. I ran 3:18:02 last October and had aspirations of beating that time in Boston next week. The problem is that my workouts (especially my long runs) have not been indicating to me that I'm capable of achieving this goal. In fact, over the past 4 weeks, the quality of all my runs has declined. I HATE the idea of bonking and having to walk/jog the latter part of a marathon. Therefore, I started thinking of running more conservatively (3:25) by running an average 7:49 pace. However "wise" this conciliation is, I'm also thinking how I always have tried to PR when I run. By slowing down, I think my motivation and excitement could be compromised. Who knows how I'll feel on race day? I could start at 7:55 and work towards the 7:49 average, or I could "throw caution to the wind" and start at 7:38, hoping that the "stars are all aligned" and that I can average 7:33 instead. Would you be conservative and give up the chance of PR'ing or take the chance of crashing and burning?