If you want to put in an original cruise control good luck. They are a PIA!!
![Embarrassment](http://67-72chevytrucks.com/vboard/images/smilies/redface.gif)
I added an aftermarket cruise control on my '83. I just could not get the factory cruise to work correctly. I spend $250 for a top of the line Rostra unit. It's the best out there. I asked several boards and all the hot rodders responsed with Rostra. Their equipment works better than the original installed. Go to my web page to see the installation. There is also a link for Rosta.
http://www.geocities.com/abetterchemist/cruise.html
These units work great on hills and uneven terrain. There are other less expensive units too. I have an $89.00 unit from
www.summitracing.com in my other truck. The unit is an Audiovox. This unit works great on a flat terrain. Mine is installed on V-6 so vacuum is a problem. On a V-8 or diesel with an extra vacuum cannister it would probably work great too. Any vacuum operated unit has it's limitations. A full electronic unit for the servo is ideal but hard to find. I think only new cars have electronic servos.