Originally Posted by bigman8u4lunch
AB injectors are split shot and AA are not. since your truck is a 97 i would believe they are the split shots but i wouldnt assume. if you can, see if you can the part numbers on them.
Only CA emissions trucks got AB's.
To tell if you have split shots (AB) or singles (AA) look under the turbo. If there is a big black disc on the fuel pump you have AB's. If not you have AA's. Or just pull the valve cover and look at the injectors, they will say either AAxxxxx or ABxxxxx right on top.