08-09-2014, 08:14 AM
Darren,
It would not be advised to plug tapped holes in the cast iron head when you'd have to drill and re-thread into the plugs. I could see where re-drilling could wander and end up with a broken tap or holes far off center. Really better to just make a new one and make it closer to the part you have.
The problem may have been in the print version. I notice now that there are no revisions to the print dated September 26, 1973. Chances are that your machine came a few months later and they'd identified problems in assembly so made changes to the parts. A pre-ISO 9000 compliant system means revisions can get lost. I think that's what happened here.
It would not be advised to plug tapped holes in the cast iron head when you'd have to drill and re-thread into the plugs. I could see where re-drilling could wander and end up with a broken tap or holes far off center. Really better to just make a new one and make it closer to the part you have.
The problem may have been in the print version. I notice now that there are no revisions to the print dated September 26, 1973. Chances are that your machine came a few months later and they'd identified problems in assembly so made changes to the parts. A pre-ISO 9000 compliant system means revisions can get lost. I think that's what happened here.