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Yes, it may be a little longer than the stock one, and the orientation may be backwards from the one you have now, but those models do fit standard ATX PSU's
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really the easiest way is to unscrew the old one, screw in the new one. Then for every old wire you take off, you replace it right away with a new wire. That ensures you don't miss any. Make sure you plug the 6pin PCI-E power connector to the new graphics card too.
Good luck!
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