Originally Posted by
Airburst
Just using a section of threaded rod, some nuts, and some washers to do it is a bad idea, because you'll probably spread one side more than the other.
Depends how much you're going for. If you're just trying to stretch a 120 spacing to 126, I wouldn't worry about asymmetry too much. Even if you only bend one side, you'd only be 3 mm off, about 1/8 inch.