I want to ad cruise to my non cruise 02 Silverado with the 6.0

I have already changed the turn signal lever out to a cruise control factory lever.

I also checked both fuse locations and insured they have good fuses installed.

What else do I need? I was thinking I need a CC servo unit under the hood. If I install that will the CC work? How difficult is it to install and are the mounting bolt locations under the hood already there?

Can some one send me a good photo of a servo installed and the connection at the throttle body.