Effillo - You're so fast, there's a good chance that 50-55mpw with "no real speed work" is enough for you to run what is essentially a comfortable pace for you. I don't know what to say about the cramping. There seem to be a lot of theories about cramping but no silver bullets. Maybe eat some bananas and drink some Gatorade and hope for the best. Based on the situation you've described, I see no reason for you to not proceed as planned.
runnerchef - Nice work getting the mileage in during your celebrations!
Free_the_thigh -If I wanted to be safe I could probably run a strong 3:10/3:05, but to be honest I’d rather put it on the line and shoot for sub 3. So the plan is to try and cross half at 1:30, and then see what happens.
Now THIS is what the sub-3 is all about. You've got balls. I like balls. Let me tell you a little story.
There was a man -- a great man -- and he was training for a 3:05 marathon. All of his workouts and paces were structured to reach that goal. Six weeks out from his goal marathon, that man ran a 10k, and his final time was 38:22. He thought the course may have been a little short, but, still, it gave him a little kernel of hope: "what if?". From that point on, it was all about the big "sub-3" that the 38:22 had miraculously dropped from the heavens. He structured his training toward this new goal, and hit his workouts with the proper Marathon and Threshold paces. He was feeling fresh, so he shortened his taper in order to get some more miles in at sub-3 Marathon pace.
On race day, he knew his goal was a long shot, but he would not be dissuaded from running a sub-3. The pace felt hard from the get-go -- too hard, even, but he did not let up. At the half, he felt the tell-tale pain and fatigue that indicated he was not likely to succeed in his quest for the sub-3, but still he pressed on. He was on target pace until the 20th mile, where a new and unfamiliar burning pain at the top of his right right quad brought fire with every step. His legs felt as hard as rocks, and agony accompanied every stride. It was a pure force of will-power and determination that kept him moving forward.
At mile 23, desperate for drink, and hobbling as quickly as he could, he reached for a small glass of water and chugged it down quick. He realized at that point that the people who handed him the drink were not actual race volunteers, and what they handed him was not water, but beer. "That's probably not what I needed", he said to himself, but still he pressed on. It was 3.2 grueling miles of grit and agony before his journey was over.
The time on the clock was 3:03:08, short of his intended goal, but he was not discouraged: although he did not reach his goal, he would never have to ask himself the question "what if?".
Free_the_thigh, don't let anything stand between you and your sub-3. Pace yourself for a conservative sub-3 and don't let your legs do anything but sub-3 pace until they physically cannot sustain the pace. You will either succeed or you will fail, but you will never have to doubt your resolve or your ability to run a sub-3 on that given day.
I have one more revelation for you, Free_the_thigh: that man was me.