bbp axle help!?

so i found a guy who has a set of bbp axles for an a body 8 3/4. they don't seem to be brand name (he purchased them on ebay). i'm wanting to use my a body brake set up. what measurements do i need to pay attention to? i know the axle stand out should be 2.25 from what i read. not sure where they are measuring from. is the center hole and flange diameter the same on both and are these off brand axles worth buying?
Thanks.