Injector Questions

[bandit_ky]

I am changing the motor in my early 99 powerstroke. After pulling the valve covers I found that there is a mix of AB and AP injectors in this motor. Was wondering what the difference in those is.

Also, the motor I bought to replace the old one is a 2002 E chassis motor. It has AD injectors only. Are these compatible with the early 99 IDM and which is the better injector to go with? I had already swapped to my old injectors since the truck ran with them, but figured I should get a little input before proceeding since I have no clue the difference in them.

thanks in advance for the help.