Did I do something stupid?

I did a bit of research on the part numbers i found. According to mopar performance, Mancini racing and Summit 4120863 is correct for the right side. Now i am confused....
According to my Mopar Chassis manual, P4120863 is for right side, P4120864 is for left side. So it appears they are not backwards. They are correct as you installed them 10 years ago.