Don't get hung up on dyno numbers.Due to different dyno's and the operators the numbers vary too much.
Most die hard guys will tell you to weigh your truck with you in it and run it at the strip in the 1/4 mile and calculate the horsepower that way.
It is easy to do and pretty accurate.
I would bet with the Xtreme Street you are closer to 400rwhp and with the Xtreme Race somewhere around 410-420.