Meprolight, now owned by Kimber, has a 3-dot tritium front & rear sight for the Redhawk/Super Redhawk, along with GP-100s which take the Redhawk front sight. If your revolver has the original Redhawk front sight, The Meprolight set should be a drop-in. The 3-dot arrangement has a tritium dot in the steep front ramp (.125" wide), and 2-dots in the rear.
David Bradshaw