IAC motor question?

Housing to tip of pintle. You want it to be less than that so it can adjust itself.

housing mark good pintle tip on gm products are rounded bevel so what part of bevel. there is no wear spot to identify where it was seated.

You measure to the tip of the pintle. That is taken from the GM service info. As was the image. GM used 3 different shapes on the pintle. Tapered, flat nosed and the ball shaped. In all cases you measured to the outer most tip. The measurement is just so that you don't damage the part by trying to tighten it down with the pintle already on the seat. So, if it's one inch it's fine, if it's at 1.25 you need to gently retract it. That way when the ECU is first powered up it will extend it until the current spike as it bottoms out, then it starts counting the steps to retract it to base idle. After that it simply shuttles from closed to open as needed.