can speed control be instaled with factory parts?

I would suggest you speak to your local Chevrolet dealership. Often times manufacturers sell "kits" that are made up of the factory components, and then the feature is "turned on" using a diagnostic tool. The main parts of the cruise control system are: * The cruise control module assembly * The function control switches * The cruise control release switch * The stop lamp switch assembly * The vehicle speed sensor You need the first 3 items, and of course hopefully the wiring is already present.