Thanks to
@03_GMC for asking helpful clarifying questions.
What you're experiencing with the Tru-Cool and towing is exactly what I experienced as well. And by asking about the restrictor, I assume you mean that you're thinking if installing a Cold Case radiator and want to know what to put in that little hose that goes back to the coolant tank. Before worrying about replacing the radiator, here are the steps I would take if I were in your shoes right now:
1/ Open up the lower grill so that air can flow easily through it to reach the Tru-Cool when you move it there.
2/ Move the Tru-Cool to be mounted behind that lower grille.
Keep everything else, including your cooling fans the way they are for now, and go do some more towing. My bet is that you'll be just fine without having to take any further steps, unless you're in the desert (115ºF outside).
If you do decide you want to upgrade the radiator anyway, all you need is a small brass fitting that will fit snugly inside the hose and has a small hole in it (1/8" is enough) to allow a small amount of coolant and steam to pass through the hose back to the recovery tank, yet is too large to slip through the hose and into the recovery tank, because that would be bad. I found such a fitting on the Dorman parts tree at my local Autozone.
As for the cooling fan motors and settings, I didn't end up changing mine at all. So that's the final step I will take if I run into any more cooling issues. I already bought the 700W fan motor for the driver's side, and the fam blade to go with it, but haven't installed it yet. I also haven't changed my fan speed settings yet with a tune.