Help finding thread for side mirror hole locations

[BrianG]

I once saw a thread where someone added some actual dimensions to where the assembly manual shows the reference locations for installing the side mirrors on a 69 C10. Can anyone help me to locate that pic/thread. I've done my searching (A LOT) and cannot find this thread. I have the assembly manual, but I need to know where to start. Also, according to my assembly manual, it looks like the top two holes are parallel to the door body line. However, seems like on doors that I have seen, this isn't the case (factory holes) can anyone comment on that?