After seeing some high transmission temperatures (especially in the mountains), I decided to install the Direct Fit Derale trans.cooler (20561). It's a good kit, designed for the average DIY. If I had to do it again, I would probably get a more generic one (and cheaper) and figure out how to mount and install it myself. I usually modify everything anyway.
For example, I tapped into the lines at the transmission instead of up by the radiator.
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