I need more room!l

I'm in the process of upgrading the cooling system in my car and I've run into a slight problem. The fan I'm trying to install is just too big. I've already trimmed the housing to the point where the blades are super close to the core and the radiator cannot go forward any more. The engine also cannot move back (yes I would do that to make this fan fit).

So I was looking at it trying to figure it out and realized that I don't use the outter most rib on my crank pulley. My question is, can I just have it milled off? I wouldn't think that if I have it cut on a machine it wouldn't affect the balance much. I think it just might work but I wanted to run it by you guys first. All I need is another 1/8 - 1/4". What do you think?

Here is a pic of the pulley in question. Sorry about the crappy cell phone quality.