[kickstand80]

I am looking for a vacuum advance for my early 1980 280ZX. I would love to find one with dual vacuum cans, but I am not holding much hope of that.

There is a VC498 and a VC499 on Amazon. These are for the Nissan Sentra but you may be able to adjust them to fit your need. You will probably not find the exact one that you need, this may be your best option.
This guy rebuilds them, he is in Australia
Vacuum Advance Rebuild