2004 nissan xterra intake gasket

[usamps]

i am putting a intake gasket on this weekend. i need the torque specs for the paleum and the intake. i have a haynes manaual. it says tighten first to 26 to 43 ft lbs.then step two 70 to 84 ft lbs....then repeat step 2. why does it have such a wide range for the torque. i have never used a tourque wrench before. any help would be great.