mike - CT,
You can buy the gears at the below website. They sell all sorts of gear ratios. The ST is the 8.8 Ford series. I was going to go up in gears until Todd Z helped me out with the Xcal idea. If your going to go to 33's though, I recommend at least a 4.10 if not a 4.56 gear ratio if your not there already.
The guys there are REALLY helpful and will explain and do ALL the math for you. Just give them a call if your looking to change up, but don't know what your going to, or if you already have a ratio picked out.
That's also where Tonka went to change out his gears. Haven't heard back from him yet, but he was getting it done on monday from what he said, so he should be getting his ST back anyday now..
~Josh