What are the rest of the late model (73 & Up) folks doing for radiators?

Check out Griffin, they may have what you need. The radiator that I am using is supposedly for a later model corvette.
I planned out my plumbing with coat hangers and I will see if I got any pictures of the installation. I think I posted it up a few years back in the what are you doing to your car thread. 2017 or 2018 is my guess.

If you are doing your own plumbing, when you are able, do two 45* bends rather than one 90* bend for better flow.

Edit;
I think this what I used

1968 PLYMOUTH BARRACUDA Radiators - Griffin radiator KEYWORD Parts & Accessories | Summit Racing