The Best Answer
Sort of. By eating SCD and training, you'll be training your body to better burn fat for fuel. (good reference is to check out the stuff (even just read the newsletters) on, also "the Paleo diet for athletes" is a good book too, both good reference to combine with 4HB in my opinion).
Once your long runs extend past 1.5-2 hours, you'll likely be depleting your glycogen reserves and will need to fuel more during those runs (using gels or whatever) or you'll bonk/hit the wall/etc. I would also try having your cheat day be the day before your long run (assuming you have 1 main one a week in your training plan) to top off your glycogen stores (takes up to 24 hours to do this, but I've noticed the day before working for me))
I'm currently training for an Ironman, I train up to 16 hours a week right now eating SCD (and actually right now I'm on the last mile and have been for several weeks). I've had no issues, but I've been eating this way since Oct 2011. I truly feel like I've changed my body to better burn fat for fuel so even when my bikes/runs get longer -I won't need to take in as many calories either. I had a VO2 test done last Dec, and have another one next week -and will share my results (it also tells you what % of calories you burn from fat vs. carbs at what heart rates) in theory I should be much improved based on my diet and training.
Also -I meant to add -I would ensure you have had a solid 3-4 weeks of SCD before starting heavy training if at all possible, you don't want to start dramatically increasing your calories just because you are running (and shouldn't need to). it's important to have that good SCD baseline set first....