My Pilgrim is at present fitted with the early type of adjusting screw, with a locknut. I would like to convert it to the later type, with a spring-loaded plunger and serrated screw head which facilitate accurate and quick incremental adjustment. I have recently converted the pump to a dripper, according the Ged Rumble drawings. I have taken advantage of it to fit two new end plates and cams (supplied by A2C2M in France). So I have to buy two new type adjusting screws and two little plungers with springs, but it is not a major problem, A2C2M can supply.
The problem is that it is necessary to drill two holes (+- 14 x 4.4 mm) in the pump body to insert the little spring-loaded plungers. (I suppose that the later type of pump body does own these holes).
My question is : did someone experienced this operation ? Do you think it could be hazardous ?