I'm not sure Carl,I can't back up that claim but just going back to my VW Bug days,they also painted the engine tinware black for a reason.
I'm sure I don't need to tell you but Black will always absorb more heat than a shiny reflective finish.

I guess I'm thinking along those lines.....

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.