OK, just to put you out of your misery....
Well, I don't know for certain. I do have a 9600 Pro Ultimate, which I presume has a similar passive heatpipe? The heatpipe is quite small and low-profile, certainly compared to the huge Zalman ZM-80, but I'd imagine it'd still take up some room.
You might get away with a PCI card directly next to it, but you may have a problem with the backside of the card as this too needs an extra half inch or so clearance because of the backside heatsink.
If no-one else answers, I'll open her up and have a play and see if I can squeeze a PCI card directly next to it or not. I doubt you'll have any heat problems though, as it is a very cool running card.
I know this isn't a great reply... sorry.