Quick Question about A-body axles

So, I have A-Body width axles, but, how can I measure if they have the correct A-body backspacing or how can I know? I thought the axles would be fine that I have, but, I question them cuz I read that some A body axles may not be the correct backspacing? I don't even know much about backspacing except that it has to do with your rim/tire. Please help me clarify this, maybe even some dimensions if possible, thanks
Author: admin