Thanks. I harvested a complete system out of a 69 Parisienne a few years ago, and installed it in my 70 2+2 rag this spring. So I've got a basic understanding of how it's all supposed to work.

The gent removing it from a 72 Chevy Cheyenne wasn't really familiar with what all was supposed to be there (ands had no ability to send of receive photo's), but it seems the underhood stuff was all present, but the vacuum switch operated by the brake pedal was missing. The electric brake switch (double terminals for cruise) was present, but the vacuum switch, it's bracket, and what is supposed to press both switches may be missing.

I was hoping an Assembly Manual would show everything, but I've been told it's not in the Assembly Manual.

Being 1972, I've also been told it was a dealer installed option. A tell-tale sign of dealer installed was the engage button being beneath the dash (not on the end of the turn signal lever), and that's what this system has. Your photo 12 of 13 seems to show the button below the dash, what are those drawings for? I just see "Chevrolet Models" in the description, and dated November 1973.

These are very good, and certainly give me something to work with. I'd stuck my head under the dash of my 72 Sierra, the brake pedal / brake electric switch is a somewhat different setup than my 70 2+2.

The gent had no ability to send or receive photo's, and didn't take visa so I had to send him a bank draft. He should get it later this week, then send my parts. Long story short I won't see the parts for a while, but will be using your photos as a guide.

Thank-you for your help.

Clint, if you don't have everything for the brake switch/vacuum switch and you don't care about original I can give you details how to do it with a relay and an electric vacuum dump valve. It's very simple, quite compact and likely easier if you are having to make stuff or substitute stuff for original parts.