Iceman Cometh: Final race of the year

This Saturday will be my first mountain bike race since May.  This could be an issue come Saturday.  Mountain bike racing requires VERY different training than triathlons.  With my triathlon training, my focus was on tempo and steady state power output and heart rate zones.   Mountain bike training is almost all anaerobic.  With my low number of mountain bike races, I haven't been exposed to the intensity of mountain bike racing.    This is by design since I had no real interest in mountain bike racing and my focus was on long course triathlons.  With that said, I'm not totally hosed for this weekend:

Swimming

Anybody who's swam competitively knows that it requires extremely strong anaerobic cardiovascular system.  Swimming can crank up your heart rate faster than any other activity.  Not only that, you heart usually stays elevated for extended periods during the swim.
Biking

Transitioning from swim to bike puts a lot of strain on the cardio system.  It takes me about 20 minutes to get my heart rate under control. Thus I'm pushing high power with a high heart rate.  Very similar to mountain bike racing.  Only issue is that I eventually settle into the high zone 3 low zone 4 during the remainder of the ride.  Most triathlon courses are relatively flat, with maybe one or two large/long climbs.

I've already noticed an impact from this.  Since September I've been training at high anaerobic levels to prepare me for Iceman.  However, the problem is that I can't recover as fast as I use too.  This became very evident during the Lowell 50 race this past weekend.  This was a 52 miles that started out with some heavy climbing and then 20+ miles of pretty flat terrain (all dirt roads).  During the climbs, I was able to push high wattage to hang with lead group, but my heart rate spiked quickly.  I was able to to grit my teeth through that, but at the end of climb, no matter what I did, I could not get my heart rate to recover fast enough.  All I could do was watch the lead group vanish.

During the Lowell 50 I did manage to find a few guys to draft off of for 10+ miles (obviously taking turns pulling).  However, once the terrain turned flat, I left them in the dust.  I just hit my groove of high cadence, high power.  I was even surprised. I thought I was pulling them, but when I turned around, they were gone.  Not only that, I started to catch up to groups of people.

Iceman is a unique mountain bike race.  It's mostly two tracks and has some flat fast areas.  It's in these areas I need to excel.  I just need to be careful because these areas are in the first half of the race.  The last half is heavy climbing.  I can't blow my legs in the first half and expect to finish strong the second.

All I can do is give my normal 125% and hope for the best.