ruby on rails - How to add story to top of pivotal tracker backlog with API -

i've got 2 situations, either high or low priority.

high-pri should go top of backlog. low-pri should go top of icebox.

in order send top of backlog, have add current_state=unstarted , before_id=[id of first item in backlog]

getting first item in backlog simple fetch /stories?limit=1&current_state=unplanned except request on average seems take 10-15 seconds!

am going incorrectly?