7zip can extract the contents from a 7zip SFX, I had to do it once because the SFX didn't work and failed to extract files while 7zip could extract it right, it seems SFX is bugged for data > 4.0 GB. So I do not trust using 7zip's SFX program, it seems unreliable, .7z just works fine 
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:: System Specs ::
Operating System: Windows 7 Professional x64
Video Card: ATI Radeon HD 5770
CPU: AMD Phenom I X4 9550
RAM: 6GB DDR2
EXP Index: 999999.999999
Operating System: Windows 7 Professional x64
Video Card: ATI Radeon HD 5770
CPU: AMD Phenom I X4 9550
RAM: 6GB DDR2
EXP Index: 999999.999999