Part number clarification

I have swapped abunch of mds for non mds lifter in chargers and have never touched the noids. But the noids stayed plugged in and tey were turned off in the programming with diablo. It really depends on if they are normally open or normally closed. If they are normally open there would not be an issue leaving them in place as they would not block oil flow. But I'm not sure that they are normally open. So once yo know there normal state that will tell you if they need to be changed. Hope my half asleep rambelings made sense.