Here's a cool little write up on bolt on dyno numbers one part at a time. Obviously the numbers will be skewed depending on the car and what dyno is used but it gives you an idea of gains to expect:
http://www.moddedmustangs.com/forum...hp-compared-real-world-numbers-dyno-here.html
http://www.moddedmustangs.com/forum...hp-compared-real-world-numbers-dyno-here.html