Hello gentlemen ! This is my first post. I have been following the forum for over 6 months. I purchased a 2006 Speed Yellow GT with black stripes a few weeks ago with 670 miles on it !:banana I'm interested in doing a tune, pulley and exhaust mod. I cannot decide on the Heffner, Hennessey or Ford Racing package.:confused I was hoping some one would be able to provide some feedback about their own personal experience with any of these companies - good or bad. I've already met a number of GT owners and look forward to making more new friends:cheers