Roadtrek 210 4L80E transmission overheating on mountain climbs

[booster]

Just a word of caution for you with the install under the van. It's location may be subject to getting hit by rocks or other debris coming off the road, and if you drive down a dirt road in the rain, you may get enough mud coming off the road to plug up the fins on the radiator. It may be high enough where it's not an issue, but just want to mention it for you to keep in the back of your mind.

Yep, underbody has plusses and minuses for certain. Higher ambient underbody air temp compared to front mount and the chance of being partially plugged up certainly need to be in evaluation.

 

[booster]

On the steep climbs 2nd gear going up with engine rpm’s about 3300 and coming down at least 3300 holding the van back

I just notice this statement. How are you measuring the rpm in the Chevy?