Joe, Autoscope Motorsports, ExaTorq Tuning& Performance, Cobb Tuning in Plano, and PRT Performance. You'll have to look up the PH#'s. You'll need a Diablo tuner to actually tune and have a bung welded in the exhaust for a wideband. These are places with Mustang Dynos, imho the best, but they are the most honest and won't give you phony numbers, let the ricers go to the other dyno shops. I have my Ram tuned on a Mustang, very happy with the results, having a pretty radical cam.
With your mods, you'll probably need to add a little fuel and adjust timing for the fuel you plan to use. Our motors will pull a lot of timing to protect from knock, if you properly tune, you will get no knock retard, motor will give optimum performance. Unless you have a Diablo tuner, you're wasting your time, though.