Best way to make an air dam for a classic car

I would like to add an air dam under the front bumper of my 66 Chevelle. The height from the bottom of the front bumper to the ground is much taller than later model cars so I'm looking for ideas of what to use that won't flex under at speed.
Anybody have any ideas or pics?

I used a first gen s10 airdam on my 64 chevelle, and cut up two to make one for my 70 duster

How big of a dam do you want?  It will affect the material choice.  Do you want: 

Small and understated: https://www.spoilersbyrandy.com/66-67-chevelle

Big ole dam: http://www.vfnfiberglass.com/66-67chevelle.htm

or something in between?

Start here:

https://www.rickscamaros.com/camaro-spoiler-kit-front-1969.html?utm_source=google&utm_medium=cpc&adpos=&scid=scplp33-255865-1&sc_intid=33-255865-1&gclid=EAIaIQobChMInJTz24OR6AIVpf7jBx128AUCEAQYASABEgLWnPD_BwE&gclsrc=aw.ds

Mr. Asa,

The Spoilers by Randy are more spoilers than air dam. Similar to the 69 Camaro  chin spoiler.

And  the VFN Fiberglass one is gigantic and race car looking.

Michael,

Thanks for the tip on the early S10 spoiler. I like the look and size of that. How did you combine two to make one? Was it for width?

In reply to 67LS1 :

It was for width. I cut one down the center, and took the needed length of splice from the damaged other. Couple pieces of angle iron as a backer, few pop rivets on the not seen edges. Never figured out how to make the seams go away, but they aren aren't really noticeable. 

Dusterbd13-michael said:

I used a first gen s10 airdam on my 64 chevelle, and cut up two to make one for my 70 duster

Holy cow, those are like $13 new. That's wildly cheap

In reply to classicJackets :

Really? They were $20 when I did it. $20 used.

They ARE cheap. Wow! 
I've looked to try and find the width so I know if I'll need to spend $13-20 or $26-40 total.

Does anyone know the width of one?