Oregon winters are "real" - yes?
I commute 20 miles each morning. Now that the ambient has dropped to below 10C in the morning the tranny pan temp reaches only app 120-130 F, so no TCC lock up. My cooling set up right now is an external cooler between the rad and the AC condenser, I have disconnected the bypass valve. I also have a valve body from ECUtune which is supposed to increase the cooling circuit flow rate. This is for the occational track days.
I will go back to the rad bottom cooler alone for the approaching winter. I may try the bypass valve during the coldest months....
If you want to monitor the fluid temp a gauge is very easy to install. I have my sensor in the drain plug.
You have all the basics correct - you just need to decide what you want. One approach is to try
. Install the tranny as it is, with the TC and all and have a taste. Just drive it !
I think you have done a good job and dug into all this quite deep - why not repair your own tranny yourself? Not much harder than swapping the pump gasket.....
Or go all the way, convert to VTD four wheel drive
. JDM trannies are available as are 3.7 rear diffs. You just need to sort out the TCU with a chip burned with the correct firmware.
Good luck,
/T