Will riding slower on climbs conserve energy?

For a long duration mountain pass ride (RAMROD), I'm worried about energy, nutrition and hydration. I have an overall time limit I must meet, but I'm not otherwise concerned about being competitive and am willing to pace myself.

I feel it's important to have the bike fit comfortably for those 10+ hour rides. I'm also a bit of a boy scout when it comes to preparedness, carrying a couple tubes, pump and roll on puncture resistant tires. I probably could shed a pound or more between tires and gear, but not sure it'd make a material difference given my size (195lbs).