9 minute miles will get you there...

Not at all, Peach. You just have to work for it. I think you've got the determination, and while you may not be able to do a 4 hour... I'm sure you can get sub-5 easily. Ok, maybe not "easy" but it's within your reach. You're young and healthy (now, right??), don't have any lingering bio-mechanical issues... You do need to get off the track and get more variety in your runs (at least as of last year I think you said you did the majority of your running on a track). I think you could do it. And live to tell about it!

Yes you can go sub 5. Train as much as you can on the course of the race. ( it is your hometown race right?) And at the time of day that the race will be held, if you can. You want your body to get conditioned to what the temperatures are like on race day. You also want to train your body to " take care of business" before its time to leave for the race, so you don't have to go during the race. Its also mentally easier when you know all the landmarks and how tired or fresh you feel at each point along the race course. If there is a tough section of the course like hills, you want to practice on that as much as you can. And even better if you can run them when you have some miles on your legs already. In my hometown race there is one decent sized hill and I ran it a lot. But it happened at mile 22 of the race. My longest run was 22 miles so I never had done it with tired legs and it was tough in the race. This year they reveresed the course and that same hill is now at mile 7, and I often run it when I already have 7 miles on my legs.

Peach, Might be able to give you better advice if we could see your log. Does your transplant limit how much you can train?

Just back from my trip actually Not having any idea how your transplant actually might affect your running, I'd hope that your doctor has ok'd the longer and faster distances. I think knocking an hour off your marathon time is a very worthy goal for the next MCM (presuming you get the medical green light). Don't think I'll drop anywhere near that much off mine. I'd be thrilled with a half hour.

In that case, I'll even offer to pace you to an even 5 hour finish at the MCM

Peach, I doubt how much I can improve too at times. I think with more time and the right training I could run a 3:50, but I would love to BQ, 3:45. I was thinking there is no way I could improve that much. A few weeks ago I ran with a friend. 2.5 years ago she ran a 3:43, last year she ran a 3:30, and expects to run a 3:10 at Boston. Ya she's fast, but the percentage of improvement is amazing. If she can improve so can we! Neither of us having been running that long, lots of possibilities for great PRs.