Whats the difference between a indent Mark O and a indent Mark P on a 99 civic power steering pump? I know where I can get a OEM one but I don't know what indent Mark the original was. The dealership doesn't even know. They both pop up in the parts list for my car. There's gotta be a difference, right

 

Has anyone been able to physically compare the 2 variants side by side to see if there's a difference?