Difference in AA and AD injectors

[E'sStrokr01]

I've noticed that some of the injectors end with an "AA" designation or an "AD"

Is there a difference in these injectors??

Thanks

[superduty4x4]

AA's are stock OBS injectors, rated at 90cc, single shot
AB's are 96-97 Cali and early 99 injectors, rated at 120cc, split shot
AD's are late 99-03 injectors, rated at 140cc, split shot
AC's are OEM stage 1's, rated at 160cc, IIRC single shot but not 100% sure on that