1/2 inch is close. I would not recommend bending the fan blades, it's a good way to start cracks and break the blade at speed, which can kill someone if your hood is open when it happens.
Problem is with finding the right fan. Makes it tempting to use an electric or a flex fan. The flex uses a lot of horsepower, and you will probably have to machine your own adapter to fit the older (larger) shaft. I was able to get the fan that came with my'54 235, believe it was originally out of a car.
