IO and Expansion Slot Dimensions

[EmeraldFlame]

Does anyone happen to know the exact dimensions of the cutouts for a cases rear IO along with the expansion slot cut-outs? I have checked formfactor.net and while they have spacing and sizing of the PCIe slots on the motherboard themselves the ATX specification doesn't seem to say anything about the rear IO and expansion slot cutout on the case, or where these should be in relation to the motherboard tray.

I have found two sources that claim to have the measurements I need, but they are also different, so I am not sure which one is reliable. Anyone have any ideas on where this info may be listed or how I can get it? Heck even if I could find confirmed correct Inventor or sketchup files that would be great.

 

These are the two sources I have found:

Source 1: 

Source 2: 

 

As you can see, these are similar but still very different dimensions.

[carolkarine]

I've been doing a lot of research.

 

ultimately the cut-out can vary so long as it allows for the bracket to mount. in such a case, refer to the PCIe specifications. I've attached them to my reply. refer to pages 75 and 76

 

EDIT: attached the file.

PCI_Express_CEM_1.1.pdf

[EmeraldFlame]

Well that gives me something to go off of at least. I am kind of surprised this isn't more standardized, but I guess I will just grab a random case and get some measurements and compare them to a slot cover.