Update to this thread:
Got the Hayden 699, worked great over the summer. Kept my temps low, and was happy with the performance. I ended up plumbing it in series with the radiator trans cooler, and I ran the 699 AFTER the radiator trans cooler.
Winter is rolling around though, and it seems the cooler is working "too well." In the 50-60 degree ambient temperature + rain, my trans is showing that it's running around 130-140 degrees while driving on the freeway. I figured that the thermal bypass on the 699 would be enough to keep the trans warm when it's cold out, but I suppose I was wrong.
I believe this is too cold to run the transmission at, and am wondering what I should do. Is it as simple as blocking off a portion of the trans cooler with a piece of plastic/aluminum? Or is there something else I can do to help my trans get up to temp without blocking a portion of the cooler?
I'm curious if others have experienced this, and what they've done to combat it.