Ditched the Electric Fan for 7 Blade and Hayden Clutch # 2765 - HUGE Improvement

What's the bolt pattern on that hayden clutch? I'm looking at getting one to run on my 340. I got a 4 blade fan on there right now that cools excellent. But makes hell of a noise and blows everything all over the place. I'd like the power and being able to work on my car under the hood without standing in a tornado.