Be the first leg if your team actually has legit competition and will probably be with a whole slew of teams till the finish, but if it is less competitive, then be anchor so you only have to go as fast as necessary to hold position. You could also just bring this up to your coach and ask his opinion, but if it is just your pr that is at stake here and not a league/sectional/championship meet then don't worry about it. You will get a chance to run fast sooner or later once outdoor starts, and the 4x800/3200 double will only get you stronger in the meantime. Talk to your coach and try to set an end goal race in the 3200 where you can really get after a time, if it really is that important to you.