If you replace the original drivers, you could have problems with the fan because the airflow does not reach all drivers correctly.

It’s possible that the new heatsinks may be higher than the older in this case the fan will be in a forced position avoiding the enclosure doesn't close properly.

Or you just don't want such a loud fan.
In this case, change the original fan for a big (100x100x12mm), slow (1000 RPM) and quiet (14.5dB) fan like Scythe KAZE-JYU slim SY1012SL12L 12V
To install the new Fan, you need print a new support piece/s, and there are two options:
1) One support piece (A) like original support, the fan will be fix with 2 screws.
2) Two supports pieces (A, B and C), now the fan will be fix with 4 screws.
The first option is easy and fast but the second is more robust, better and more complicated.

The files are for Trigorilla 8-bit (The drivers are not soldered)
Fan_Support_A.stl
Fan_Support_B.stl
Fan_Support_C.stl

For more information, see the detailed instructions in PDF here
PDF Erratum: On the first picture at the section "Option with two supports", I marked the single black screw with M3 x 15 and the four screws for the fan with M3 x 25. is the other way round. (Thanks to R3AL3X for the feedback)

If you like this project, please consider supporting me by sending a tip on thingiverse or my PayPal here

26-11-2018
Uploaded the version for new i3 Mega V4 mainboard:
https://www.thingiverse.com/asset:118024

Thank you to Hawker2007 for test the fan support modifications.
https://www.thingiverse.com/make:569049

14-06-2019 (edited 03-11-2019)
Uploaded new support A (original i3 Mega) for these size fans:
100x100mm x (10 or 12) mm only if have holes for 92x92mm
92x92mm x (10 or 12) mm
80x80mm x (10 or 12) mm (For this fan only need new support A)

https://www.thingiverse.com/download:6642034

05-01-2020 (edited 30-09-2020)
New release V2 for fan support 120x120mm x (10 or 12) mm and holes 100x100mm
The files are for Trigorilla 8-bit (The drivers are not soldered)

Fan_Support_120x12_V2.zip

This version are tested review the "makes section"

16-01-2020
Update the support for size fan 92x92mm x (14 or less) mm and holes 80x80mm.

The new V2 version files for Trigorilla 8-bit (The drivers are not soldered) and low heatsinks:
Fan_Support_92x14_A_V2.stl
Fan_Support_92x14_B_V2.stl
Fan_Support_92x14_C_V2.stl

Note: Print with 75% infill

If the heatsink is high, check this thingiverse:

https://www.thingiverse.com/thing:4667673

30-09-2020
Added tests to check horizontal expansion before print the supports.

Test_Fit.zip

Print all the test STL files and follow theses instructions that you will find inside the zip file.

If it doen't fit, please modify the horizontal expansion on your sliccer, print again and check.
All STL files must be printed with the same horizontal expansion.
When all fit tests pass, then print the fan supports.