I could only find dimensions for one of the amp boards but it is too large to fit that enclosure:
Features:
Stereo or Bridged Configuration
Power On / Off Switch
Power and Error LED’s
click and Pop Noise Reduction
Over Temperature Protection
Over / Under Voltage Protection
Over / Under Current Protection
MOSFET DC Protection
All Housekeeping Power Supplies
Small Size: 4.5” X 4.25” X 1.25”
Made in the USA by us... classDaudio.com
Best,
Ed