The thread Bird referred you to may tell the whole story...but I did not feel like reading it again to find out... /forums/images/graemlins/blush.gif
The way I see it is that the tail wheel sets the height of the back, and the height of the 3PH set the mower height in the front...if it is the 3PH type and not the pull behind type.
So I would set the tail wheel to get the back at the approximate height I wanted the cut to be, and set the 3PH so the front was about an inch lower...or add an inch to the back...you know what I mean... /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif
Fairly simple really when you think about it.
Good luck and be careful. Do a search or the archives and you will find a lot of important safety tips for rotary cutters...