A model for mounting a 120mm fan has a comment saying it's also insufficient, so there's that. Seems like a snail blower is maybe the only option, and they're so long I don't think it'll fit in this case. At least that's what all the GPUs with built-in cooling use, though, so at least I know it's the right amount of air flow, and I need a bigger case, anyway, so I can install the second GPU (because if I can't keep one cool, why wouldn't I double the amount of heat to be dealt with?).