Raise the front sight or lower the rear sight - both or either will make the gun shoot lower.
The front sight movement is always opposite the direction you want the ball to strike. ie: Drift it to the left, it now hits to the right, drift it right, it hits to the left. Raise it's height, it shoots lower, lower it and it shoots higher.
Appears the new front sight is lower in height than the old one.
2 feet is a lot - WOW! Perhaps something else is adding to the elevation, as perhaps the lube you are using is slipperier than the lube used when originally sighting in the rifle?