A question was posed to me via PM ( I won't identify the poster )...about the validity of my comments on using the top hole of the 3pt rocker.. at the time, I gave my answer based on experience, but didn't reference a 'book'.. so.. here is the book reference:
8n owners manual, reprint, 1952 edition.. page 115... refers to using bottom hole of 3pt rocker for heavy loads.
1952, reprint, NAA owners manual, section 8, pages 66 and 67, hyd operation. Refers to using draft control with ground engaging implements, and position control for objects operating at a set height ( mowing!!! ), also again reafirms that heavy loads go inthe bottom hole, and light loads go in the top hole.
Soundguy