Before making any changes it is advisable to try and fathom out what is going on within the kingpin assembly.
In general terms, the individual loads on an assembly will only be transmitted between fixed and moving components in a relatively small proportion of the assembly.
It is important that these load-bearing areas are lubricated properly, otherwise free movement is compromised and wear is accelerated.
In joints like a kingpin, engineering practice is normally for any grooves to channel grease towards, and sometimes right across, the load-bearing areas. Because the grease is only replenished occasionally, the channels may also act as a grease reservoir.
On the other hand, it is equally important that load-bearing areas are of sufficient size, and not overloaded through being compromised by any grooves etc.
In a kingpin a number of loads are transmitted - including the weight of the car, cornering and braking. All of these loads are variable and, as the car is steered and braked, the load lines between components will also change.
Therefore, before making any modifications I would strongly recommend you look carefully at the loads and where they are taken, and ensure the arrangements for lubrication are adequate and not compromised by any changes.