Marathon running

Are you looking for a stand alone marathon training plan or figuring out the run of an Ironman?

Agreed.  If you are doing Ironman, you DO NOT want a stand alone marathon plan for your training.

The Hal Higdon Novice running plans are not really hard.  I would think that they would be fine to use on top of your swim/bike training for an Ironman with out too many adjustments required.  His intermediate and advance plans are probably too much to do on top of the Swim/Bike training though.  His intermediate is about the level of most stand alone Marathon plans.

The training really shouldn't be much different than your training for a half marathon.  Your long runs will be longer as will some of you other runs.  The pacing and nutrition is the biggest difference between a half marathon and a full marathon in an stand alone 1/2 marathon and stand alone marathon.  Most people can store enough glycogen to fuel their body through 2-1/2 hours of intense running (zone 3).  If you are finishing a 1/2 marathon in more than 2-1/2 hours you probably are not in the "intense" zone (and are in the zone 2) so really most people can finished a half marathon with out a planned out and tested pacing and nutrition strategy.  In the full marathon that isn't the case.  If your pace is too fast you can't refuel efficiently and you will crash before you get to the finish line.  If you don't take in the right things during the race or take in too much your body could respond badly and you will not feel well and want to stop and walk (or stop and throw-up).  If you don't get enough nutrition in, you will run out of glycogen and bonk. I am told that the Marathon in an Ironman is different than a stand alone marathon because you in a zone 2 (69-83% thresh hold HR) rather than a zone 3 ( 84%-94% thresh hold heart rate) where you burn more fat (extending the glycogen storage) and refuel faster (again keeping you glycogen levels up).

I haven't read the Matt Fitzgerald books, but I know that his are some of the most popular on sports nutrition for Marathons and Triathlons.  I just did a search and see that he has a book called The New Rules to Marathon Nutrition.  That might be the one that you need.  His Race Weight is one that was recommended to me when I had question about nutrition for half Ironmans.

When it comes to the Ironman run, I always use the word "run", I never use the word "marathon", because the only thing in common between an Ironman run and a stand-alone marathon is the 26.2 mile distance. I've done multiple IMs and multiple marathons, and there is a WORLD of difference between the two.  You start a marathon standing at the starting line fresh with only 26.2 miles before you, rested, hydrated, warmed up a bit, ready to go.  You start an IM run coming out of T2, just finished your 112 mile bike, you may have a bit of rubbery cycling legs, your on-the-bike nutrition for the last several hours may or may not be working, etc.  You get the point.

The training is different too.  A triathlon is one sport comprised of three events in sequence. There is some value in training for the swim like a swimmer, training for the bike like a cyclist, and training for the run like a runner, but most of it is in technique.  As was said earlier, a stand-alone marathon plan is not like training for an Ironman run.  IM training plans need to balance the training and time between three sports, and most are more bike focused than run focused (because that's where the time is spent).  Marathon plans obviously focus on just running, and will have you running WAY too much for an IM. 

It's my opinion that too many IM athletes end up over-focusing on the bike to the point they are under-trained on the run, and if they'd just put a bit less training on the bike and a bit more on the run, there would be a lot fewer walkers on the IM course. It's so easy to overcook the bike and walk too much on the run and kill your overall time.

The older "Going Long" books IIRC have a pretty good run plan.  I'm a fan of Fink's approach to overall IM training he covers in his "Be Iron Fit" books.  For marathons, Years ago I did my first few marathons using Hal Higdon type plans combined with Maffetone type HR-based pacing and training.  I've not read the Jack Daniel's books, but I've done a lot of run training with paces based on his v-dot approach and the http://www.runbayou.com/jackd.htm pace calculators. 

Good luck in Cabo.  I did it the first year it was raced and the bike was harder than expected for most people and this hurt overall times. They have a different bike course now, but I think the run is the same.  The run is super flat and easy as IM runs go.

x3.  I'm confused by your post.  The subject is "Marathon Running", but the only race you mention is the IM.

What are you really asking?

It's a well thought out response.  But it is from a runner who has never done an IM.  I suggest posting some more information about your background and current abilities in the 3 sports.  Then you will get some much better suggestions on how to proceed to plan for your IM.  From what you have said so far, it really sounds like you are asking the wrong question and need to take a step or two back before assuming you need a marathon training and nutrition plan.

While you are running in both parts, there are some rather notable differences. As noted, the prior response has some nice thoughts, but for a marathon and training for that. You are looking at running as part of a much longer event. You'll be running longer and at a lower intensity after already being in a rather fatigued state at the start of it. Also consider the training. The Novice plans may not be that hard for a solid runner, but I have seen more than a few novice runners have to push themselves to get through them. That's also when marathon training only, not Ironman training. A novice plan will be much harder with all the swimming and biking that needs to be done. And it's really necessary to get through those two well to have any chance of running well. Another reason to look at the IM planning as a whole is that you will need to push and recover in each of the three disciplines. Being fatigued from one will affect the others.