Sorry to come in on this post
My 350 Chev has a cruise option on the LH steering column stalk..
I have rebuilt the Rochester Carb, and although I have not connected every vacumn unit, I can't really see much that will hold the throttle open.
On the thottle pedal itself, there is a slide sensor device.. I assume this measures pedal position.. two questions,
Is the pedal postion to do with basic electronic ignition timing? (thought vacumn was use for that)
and, does it sound like there is no cruise fitted, just a button for it?
Any help always appreciated, I am learning