correct me if i'm wrong but a t-pro has a 60mm steerer tube so measure your stem (the inside of the clamp) add that to that and any spacers you'd like to fit, take away say 5mm from that sum to stop the stem cap touching the steerer and cut it to that length. (Y)
before you cut them take a screw driver and a hammer and knock the star nut down just below where your going to cut!!!
or just take it to your local bike shop :lol:
hope that helps