REMEMBER: Only use heatsinks that use the bolt through style. Not the retention clips.
That 80lbs or whatever is when the IHS is on it, not the core by itself. I don't know how much the cores can handle, but the way I see it is, there's no reason to make the cores weaker just because they have an IHS on it. I'm sure the cores are just as strong if not stronger, but certainly not weaker, than the exposed cores of the K7 days.