Jeff - I'm not much help here, but here are my thoughts. I'm not sure if they were available for a Chevrolet of that vintage. It does seem like it would be difficult to retrofit those as they get wired into the entire wiring harness.

A visit to the local Chevy dealer should answer your question. Chris is correct about the wiring. I had a 2013 Charger that came without a compass which I wanted. I asked the dealer what it would cost to add one and was told it's not possible (at least not for a reasonable cost). Car companies are so big into option "packages" that it can make it difficult to add things. In my case, adding a compass would have required adding a whole new sensor package.

Sorry for the long delay in answering your responses. I did go to a Chevy dealer to inquired and it seems it would be extraordinarily expensive to retro fit a factory set up. It would even involve replacing the entire computer system since almost everything runs through it. Aftermarket systems are available from places like Summit Racing for street rod applications. These are not expensive but also not like a factory setup. Thanks again for your ideas.

Jeff