I have a 1987 Chevy truck that didn't come with factory cruise, but I
have what I think are all the pieces, including a new wiring harness
(got it from a dealer, but didn't end up paying--long story).
If anyone has an '87 truck with factory cruise, I'd appreciate a couple
of digital photos--one of the cruise servo under the hood, so I can
figure out how it's supposed to be mounted, and one of the brake pedal
showing the vacuum and electrical switches. If the cruise module is
easy to get to, one of it would be great, too.