With IDI pressures there is no (efficient) limit with an 11mm plunger
i drived a 11mm plunger and never had any problems, i seen 6000 much times, just cause its cool. (i dont know how agressive my camplate is)
the head and the plunger always need to be toghether, you cant use a other plunger with the same head, even not if the part numbers do fit.
Why the camplate, you can get so much diesel with a 11mm...
anyway, if you do use another (higher lift) camplate you need to use the 2 (stronger) springs also.
Try to make it running with stock pump and just only a 11mm, you will see it can be hard enough :wink: