It's a little exaggerated to prove a point, but you can try to apply the concept as best you can.
Maybe put a more gentile radius on the back instead of 90°.
Try to copy similar to the stock plastic geometry which is limited depth also.
You should have some depth to work with, as now you don't have a mechanical fan hanging off the front of the water pump and can use some of that depth....
Try to add a little more radius to your bends for the back face instead of sharp corners. A little more radius can help...
