Will this crankset fit my bottom bracket? I've got a 2004 Trek 4300 that I need to replace the crankset on. I was able to look up the bottom bracket size here and see that it's a 73x122.5.

I'd like to buy this crankset but I'm not exactly sure how to know if it will fit or not? The specs say:

Square taper crank accepts 68x122.5 mm spindle


Does that mean it will not fit mine which has a shell size of 73?
It will fit. 

If you need references: If you look at the Shimano Tech Doc, it suggests the Shimano BB-UN26 (which you can find that you can fit it in that version).