I've done BMDM heavy four times previously. I think a 20+ miler with your pack might have been a good idea earlier, but you probably don't want to do one this close to race day.
The hill is certainly annoying. According to my Garmin tracks you hit the lowest point about six and a half miles in, then there's a small climb and some level, then another small climb and some more level, then about nine miles in you're climbing consistently until about thirteen and a half miles in. If you train based on heartrate, you'll automatically adjust your pace.
The thing that got me the first year (other than the fact that I was a lot less fit than I am now) is that course itself is mostly very hard-packed mud/dirt or asphalt. I trained on softer ground and my feet weren't prepared for the beating they took. I was only planning on hiking most of it and only running some of the downhills, but I wore hiking boots and could barely walk twenty miles in.
I have done better each year and have adopted the following training schedule:
Between BMDM and November, I try to do at least one major long event with my pack (e.g., hike the crest trail with a 40 poundpack) once a month, just so I don't lose too much of my "pack legs". Starting in November I do a pack run every Saturday and every Wednesday.
My Saturday pack run alternates between a long-distance run on level ground (with a 40 pound pack) at my goal pace and a run five miles up the La Luz trail and down again as quickly as I can (with a 35 pound pack). The level ground distance increases each week (except when I'm tapering, racing or recovering from other races). I topped out at 24 miles a week ago.
My Wednesday pack run is from my house out to a local 3.3 mile loop, doing a lap or more, then back to my house at a pace about a minute faster than my goal pace (with a 40 pound pack). Like my level-ground Saturday pack runs, the distance increases over time.
Sundays I ride my bike (distances increasing up to 70 miles) @ about 130bpm heartrate. Mondays I run 12.2 miles @ 130bpm. Tuesdays and Fridays I run 3 miles @ 130bpm and Thursdays I run 5.6 miles @ 130bpm.
I take ice baths after my Saturday and Wednesday runs. I could not push myself as hard or recover as quickly for other things without them.
I do a 15 day taper where I do all of the above, but at half distance for the first 7 days of the taper, then all of the above, but at quarter distance the next 7 days and typically don't run at all the day before the race.
I am not suggesting that my training schedule is the best for you, but it's more or less what I've done for 2012, 2013 and what I'm doing for 2014.
Good luck.