Kickdown Lever - Locking in Place

Just a quick question. My buddy lost second gear in his trans so I am letting him borrow my 727 that was laying around. His was a manual valve body, mine is not. He doesn't have the linkage for the kickdown installed, since it wasn't needed on his trans.

Can he just wire the kickdown lever on mine back all the way and run full pressure all the time?
It'll probably shift into high about 100 and it will have really harsh down shifts that could hurt the transmission, so no I wouldn't do it.