I used super glue in 2 diagonal corners of the Northbridge, and a thin layer of generic thermal paste throughout the rest of the contact area. Used an old 486 heat sink, and it seems to be working ...

Just picked up a 3.4C northie for my good old Abit IS7-E (July '03 vintage).. Anyways, it's an SL793 D1 stepping chip, with a factory Vcore setting of 1.55V.. It seems to have more than adequate ...