Thee are a couple aftermarket tuning devices out there,
the Tweecer is one.
I looked into getting one of those and learning how to use it,
but have been informed, and have seen from reading the
sites and especially the tuning forums, that it's VERY learning
intensive. Not to mention over $400 worth of hardware.
I decided that, since I'm not going to be changing my setup
frequently and not needing to do a weekly tune for the track,
that I'd just go have a good dyno tune done. About the same
initial outlay, but if you get a good tuner that knows what he's
doing, you probly end up with a better/safer tune anyway.
I did a Google search for dyno tuners, Mustang dyno tuners
in my area, and also posted questions on several Stang boards.
Came up with one that was highly recommended, emailed him
with some questions, now am all set up to go get my tune.
I usually like to "do it myself" but I feel the time needed to learn
to use one of those things effectively is more than I care to
commit to.