Updated
I took a road trip from indy to Evansville again about 70 outside temp and running 80mph with the OD off the tranny temp stayed about 180 with the OD on it went to 210 rather quick.
Conclusion with that cooler I have to run with the OD off, which isn't that bad considering the motor is underpowered anyways with oversized tires , wind stopper of a roof rack and the genera, vehicle weight to power ratio at 80 I was about 3600rpm which isn't ideal but won't be too hard on that motor.
I also concluded that even a bigger cooler wouldn't help considering that in 30 seconds it would jump to 210 and be on its way to 240.
Does anyone run a scan gauge II with the factory cooler? I would be curious to see what temps you guys see?