Injector setting

[Pro Star Cummins]

Hello: I have a question on injector settings. We have ISX 871
And popped lid to adjust valves and injectors. Every thing
Seemed normal on valve settings until we did injector.
The adjusting screw was run down to where it just made
Contact and was then locked in place on all injectors.
There was no inch pound pressure at all. We set them at
70 inch pound according to valve cover setting. We had
Approximately 1/2 inch difference more from their setting
Mark to our setting mark . We bought Trk used and International
Dealer had replaced Injector cam and 2 rocker arms. It is
A 2008 Pro Star. We've run it 2 years not knowing about these
Inector settings. How can this engine have run like this, is there
That much leeway in settings ? We followed Rawzes vidio which
Was a great help (Thanks Rawze ) . Has anyone experienced this,
Or is this a fluke ?