It's hard to "find out" what size tires will fit a fork, unless the seller is willing to test-fit the size you need. I believe when I read the ad for either the nashbar or Performance fork, it listed an axle-crown distance, but I didn't know if it was the inner measurement or what. I think I needed 272mm and they listed it at 274. Whatever it was, I was taking a chance and knew it.

I got my fork from a BF member, by the way. He made my month.