If you already have the GM column with the button you might consider the GM style I'm using. I pretty sure the built in button serves the same purpose that the solenoid I had to built.

Here's what would be involved. You will need a transducer, (available rebuilt for about $75). New Speedo cables, one from the trans to the transducer one from the transducer to the speedo. A vacum pod and bracket. My Pod and bracket was used and came from a Mid 70 Chevy Van. The bracket was simply mounted to one of the bolt that hold the rear water passage block off plate on.

The linkage from the van was also modified to connect to the carb. You will also need a brake peddle mounted switch. It acts to break the circuit to the cruise and shut it off and also has a vacume port that dumps the vacum in the pod the release the carb linkage. Finally you will need either a piece of resistor wire or a balast resistor. If yo can find one they make a combination switch that has a plug for the brake lights, the cruise circuit and the vacume dump. It should bolt in in place of your brake light switch on the peddle.

After you mount the transducer and connect the cables you will need to run 2 wires from inside the car to the transducer amd one vacum line from the transducer to the brake pedddle switch (if your running a stick like I am your will need a switch on both peddle and have to "T" the vacum line.

Once you figure out where everything goes you should be able to install it in a Saturday.

If you think you might want to give this a shot I'll see if I can scan the wiring and vacume diagrams and E Mail them to you. (It might take a day or 2 to get that done though).