68kMLA

Heat-pipes are the only innovation I can think of that came after the 180's time. Maybe slap a copper heatsink on.

The chips in those don't run very hot at all - there's no need for better cooling in them.

Yeah, I know those chips run cooler, but what if your OLD heatsinks got damaged? There should be a guide somewhere on using new, suitable equivalents.
Perhaps that's something I'll have to figure out myself (I know nothing about PC cooling!).