If the KK shove was on this blind level, it's fairly standard. If it was on the previous, then I'd suspect that's an indication he's one of the never fold top pair, never never fold an overpair donks.
Either way I call, because I want all his chips [img]/images/graemlins/smile.gif[/img]
Aside from other reads I'd generally not raise with more than 20x BB in both stacks.
IIRC HoH suggests calling up to 1/10 of your stack for set value.
There are a few decent articles on this on
Full Tilt