You've got things a little backwards, or mixed up. It can get confusing.
The front sight should be adjusted in the
opposite direction, from the way the POI must be adjusted.
The
rear sight should be adjusted in the same direction the POI must be moved.
If your peep is all the way down, and the .343 front still gives you a POI that's 22"high, the .343 is gonna have to be switched out to a .500, or more.
You definitely need a
higher front sight blade , and the correct height can be calculated, using Brownells Sight Height Calculator. (click/scroll)
http://www.brownells.com/aspx/NS/GunTech/sight.aspx