As Jim indicated, you should measure the bolts to make sure they are not already stretched beyond spec. They are usually good for a couple of additional torquings after the first one at the factory.

Either make paint marks on all the bolts before you start, or make SURE that you are not interrupted during the sequence and lose your place. Also get ready for a workout and get ready for the fact that you will think that you are going to break the bolts. Don't use a torque wrench for the 90 degree sequencing, you will ruin it. Get a good quality breakover bar.

Good luck,