old car egr help wanted!

I'm working on a '78 LTD w/302 engine. Somewhere along the line all of the emissions stuff was removed from the engine, and a plate was put on the egr port. So, I'm trying to see what it would take to either install the complete system the way Henry built it, or at least put in a working rudimentary egr system.
My first thought was to go to RockAuto.com and see what parts they listed, but they don't offer much beyond the egr valve itself. They don't even offer a vacuum thermal valve. If I remember my basics correctly, a basic system needs ported vacuum, a thermal valve, and the egr valve itself. Right? What else would I need for a basic system?

Is'nt this car exempted from emission laws?

Daniel may be right. Before buying anything for emissions regulations, make sure it applies to your vehicle year in your county.

Old, mechanical EGR systems were complex and flawed, with many resulting drivability problems. Imo, unless its necessary for emissions compliance, adding an EGR system is an unnecessary expense and can open up a big can of worms regarding drivability, performance, stalling etc.

Yes, its nice to have an all-original car, but older EGR systems are not helpful.

Finally, if you are simply concerned about the environment....... drive the car less often. It is what the EPA calls a "gross polluter" regardless of how well its running, or what equipment is included. :)