Let me know if they work that way when you get them.
I have Carter and Son's J-Hooks welded to the top of my 3pt arms, and currently use the turnbuckles along with a rubber strap between them to keep the same width on the lift arms.
That works pretty well, except on my brush hog the strap gets in the way of the pto so I have to remove it when hooking up.
I've set all my attachments to have the same pin width, so if these stabilizers would hold my desired width on the lift arms I wouldn't need the strap.
I think he say's these are for up to 35hp and mine is 42hp but I doubt there is any weight difference so I'd think they would still be fine.