Radiators: Is 22" enough for 400 HP?

From the sounds of it, it may see that a 22 inch radiator with a 1 inch tubes may be adequate, but what concerns me the most is sitting in bumper to bumper Los Angeles traffic. That can easily make temperatures rise, especially if it's in the summer time.

Another thing that I read is most of the aftermarket aluminum 26 inch radiators are for B bodies therefore a bit too tall for A bodies, which requires some modifications to the lower portion of the core support. I've read where a few members had to take a hammer to it, or cut some metal off. Should this be a big concern?