Some of us long time members have a personal theory or experience with this and stick to that. Here is mine.

If drive shaft rpm exceeds 2500 rpm on a NP200 for more than 30 minutes 9 out of 10 will over heat. Even with synthetic oil and a direct drive conversion.

Either keep below that speed which is 48 in a stock truck with stock tires, rebuild the transfer case which seems to fix it for just about every one that reports back or get a different model transfer case.

I found a divorced 205 after mine would get hot. But, while still driving the truck collecting parts and pieces I discovered anything faster than Warp Speed is just noisy with so much more buffeting with the top off. I decided to just drive slower and enjoy. If I need to get somewhere fast I drive something else or plan ahead enough to take the M715.

To me that is what this all comes down to. If speed is your goal, the M715 will never satisfy in my opinion.