Well, I'm no expert, but I would expect that on a socket 771 processor, "Pin X" performs "Function X" and "Pin Y" performs "Function Y". I also expect that on a socket 775 processor, "Pin X" performs "Function Y" and "Pin Y" performs "Function X". The pin mod sticker probably fools the motherboard socket into thinking each pin is performing the proper function.
I have heard that LGA 771 Cpu can work on a LGA 775 Motherboard with a Adapter
My Motherboard Chipset is MSI G31 Max TDP 95W. So can Xeon E5450 work on my LGA 775 motherboard with a Adapter
I have this same motherboard. If you flash to the newest bios, then do the physical mod described in the article, then YES, the lga 771 DOES work! As a matter of fact, the MSI G31 is one of the easiest boards to mod for the Xeon! If you need help, join us in the lga 771 to 775 Support Group. I'm about to revise the article for rookies like me. The 2.8 bios WILL support the quad-core. That is the same cpu-family I am using.
Im on a Asrock g31m-gs motherboard im using a e5310 xeon but it showing only 2 cores and in core temp it says 5110 wood-crest but cpu z says clover-town e5310 i thing i need to change the micro code im also at 1.2ghz bios is v1.9 i have a g31 chip-set like you so try it if it doesn't work update the bios and test again