Bill …
Years ago I had a hydraulic top link on a rear mounted land plane (grader)… on that it was very handy, I have also used it with a box blade.
I didn’t have the check valve system just hydraulic cylinders. The checks may be important for your application. I was watching closely and with constant change in top length and lift, I didn’t really miss them.
Like Glenn suggested you will find lots of opinions about type, length if you search, TNT or top n tilt, Henro is building a trick set … he has had hydraulic hose supplier problems. I myself would guess you would want to be about mid stroke to equal the factory settings. This would allow you to go longer or shorter /forums/images/graemlins/cool.gif while using your 3pt. KennyV.