m923a2 rear of cab question

[AMF1972]

Hi all... Can anyone tell me what the two vertical metal "straps" on the rear of a 1987 M923a2 are for? And, would it be a bad idea to mount the stack to the one on the passenger side? I know these trucks flex a lot, so I wasn't sure if using that part of the cab to mount two brackets for the stack was a bad idea...

 

[NDT]

The machine gun mount legs are attached there.

 

[AMF1972]

Ok, that makes sense... Thank you!