VZ, this is gonna get scary....you ready for this? Well, first, any tranny cooler would be great. ANY. About the same size as the stock unit. Even the small ones will be a benefit, but better cooling costs more money. I spent about forty bucks. Do the 180° Stat at the same time, though.
Now for the fans....the ECT is nothing more than a thermistor. A resistor that changes value depending on temperature. To get the fans to come on sooner, you have to trick the ECM into thinking it'* hotter than it is. Easy, right? Yes, it is.
About every 20° change equals about a 100 ohm difference in thermistor resistance. For instance, 212°F is 177 ohms, and 194° is 241, 176 is 332, and so on. As you get to the bottom of the scale, it'* not so linear, but we don't care, because the fans come on at the higher range, right? So if you want your fans to come on at 20° cooler, you simply splice a 100 ohm resistor in series with the thermistor. The same trick can be done with the IAT.....if fact, kits for the IAT are sold commercially. You can do it yourself quite simply. Try this one.......you can use a switch to make them come on when you want, but then again, auto is better.
Any of this help?
BTW, VZ, I gotta know.......go here: