"Real" wheel diameter I have a 1983 Bianchi Bici 4, which I long ago converted into my errand bike, and the only one I'll lock up anywhere. 
It's got 32C tires on it right now, but they only just barely fit in the frame with a bit of coaxing. The chain stays are about 3/16 away from the sidewalls, so I'm ok if the wheel is true. The problem is that the top of the tread is incredibly close to the bottom of the brake, as well as the clamp on the changer. Too close, in fact. 

So, are there any 32C tires that will result in a slightly smaller overall wheel diameter when inflated? Montreal roads are notoriously bad, and I'd still like to use the fattest tires possible. 

The bike was originally equipped with 23s, so clearances are very tight everywhere. 

Thanks.
Even if someone had a magic database of actual versus nominal sizes for tires, they would need to know what tires you have now and their actual inflated size on your rims to answer.

The best answer is yes, probably there is a nominally 700x32 tire out there that's smaller inflated than what you've got. But, two issues there: tire manufacturers have gotten much, much better than they used to be about accuracy in size labeling, so finding that tire would now be a challenge. Secondly, manufacturers often correct badly size-labeled tires pretty readily, so even if there were a good recommendation out there, it would be a bad question for an SE site since it would be a product recommendation that's highly subject to change.

A better approach may be just get an accurately sized 700x30, which is an existent albeit not super common size.