Shift shaft lenght-general question-140 johnson 87

[SD Black Sheep]

Trying to get my lower unit back on and hooked up correctly. Shift shaft got adjusted and having trouble finding right height in neutral as manual states. I have measured to height requirements for engine but things are still off. I noticed it seems like neutral has a range of height options. I have measurement done in neutral then pull drive shaft up to check forward, put back down to check neutral and the height is now different in neutral now. I know the measurement for shift rod need to be exact any advice.

Seems like neutral has a wide range how do I measure in neutral to exact measurement?