If you've got an '87-'98 Chevy/GMC pickup or a TBI 305 equipped Camaro, here's a great way to squeeze more performance out of your factory throttle body, especially if you're upgrading the engine's performance...
R.V. Morse Machine has been in the business of improving factory throttle bodies for over ten years now. They can increase the airflow on almost any type of throttle body (for a reasonable price too), but htey first got their start massaging and increasing the flow rates of the GM TBI units. Recently they added a new ASNU injector servicing center, so you can send in your fuel squireters to be ultrasonically cleaned and flow tested for maximum perofrmance.