[M_a_t_t]

I'm not worried about losing drag as much as the tucking of the radiator. At this point the car has become a balance of what I want to experiment with and best fuel economy. The fuel economy is just the practical benefit/side effect.

Cooling System Basics - Keep It Cool - Super Chevy Magazine

I read this article and it seems the basic factors are thickness (thickness or the core and number of cores) and the area. The material is of course important, but it also says all modern radiators typically use the same design so I shouldn't have to worry about the material. So it seems if I know these numbers from the stock radiator I should be able to come up with a reasonable guess at what would be adequate as a replacement.

Does that logic work out for everyone else?

I also realize it would be a lot of work, but until I take it apart and look at the details it's something I want to consider