I can't remember, did your new e-fan setup help with the cooling issues you were having while towing? Or did you even get to test it out yet?
It surprises me that you were having cooling issues. With this tuned 8.1 towing the slide-in camper, and my blazer behind that with gear/tools/spares, and even a ford d60 thrown on the trailer (we were estimating about 18k GVW) and mine never got above 190* once. Stayed cool as could be the whole time towing, even in 85-90* heat. And again, all I have is a 9-blade mechanical fan with a BBC radiator and shroud on there.
I will say though, I have heard stories of guys who try to tow with only e-fans and no matter how much their fans are rated for, it still can't seem to keep up with what a mechanical fan can push. Lots of guys I've heard say driving around like normal the e-fans do just fine, but it's kinda hard to get better air flow when towing then with a standard mechanical fan. Just food for thought I guess