i've already got my sb, nb and mosfets cooled, but contrary to what you say, the south bridge is actually hotter than the north bridge - the nb is at 1.45v, the south bridge is set to the lowest voltages (1.15v + 1.5v).
i'm going to pick up some jb weld today so hopefully i can stick the damaged 120.3 back in and use that for gpu's and sb/nb.