Old Meyer plow mount

[pocojo]

Can anyone advise me as to what the three vertical hole positions on this plow mount are used for . Thanks

 

[macleanflood]

 

[Blue Clearwater]

Can anyone advise me as to what the three vertical hole positions on this plow mount are used for . Thanks

View attachment 667198

Changing the height of your mounting point. It changes the angle of the blade in relation to the ground.