I see. I don't know why the find command would be missing, but we don't need it for this issue i believe.
The other games you play are probably even less demanding GPU wise, because they focus more on graphics and the engines are optimized for performance.
Removing any parts of the case might actually destroy the airflow and render some Fans useless.
I suggest we do some measurements for the GPU.
Please download
GPU-Z.
Start it, select the "sensors" tab, and activate "Log to File" at the bottom of the window.
Choose a location for the log file.
Now run the game until it crashes.
Then
Zip the file and attach it to a reply in this thread.