I dyno'd mine on a Mustang dyno last year. Numbers were on the disappointing side, but don't know if it was the dyno or the car. Completely stock at 1000 miles, my '01 GTS dyno'd 396HP / 414TQ SAE corrected down since it was a cool day. Torque in particular seemed way low.
I did make a couple of mistakes which may have affected the dyno numbers, like running with the hood fully open, which probably blocked the cooling fan from getting any cool air to the intake. The engine was also on the warm side. Now that I have a few mods and more miles, I'd like to get back down and check it again on another dyno to compare.
--- Ken