I don't know what instructions you are using to try and adjust the 8N lift but it has been my experiance that most of them simply can't work on a 60 year old set of parts.
All I have seen you have to have the lift arms all the way down in order to adjust the position mode. Or with the ram cylinder removed the lift arm yoke pin holds parrall with the lift cover gasket surface.
What you really need is one of my lift adjusting jig fixtures and my experianced method of adjusting the 8N lift so you have a solid place to adjust to.
See the link below if you are interested.