Dovetailed sights are in the 3/8" range. The slot would show.
If you just want a dovetail front sight, since it's a stainless gun, just have the ends of the slot Tig welded to fill them in. Dress down and polish, then cut the dovetail.
Or if the front sight is so far off, that the rear sight adjustment puts the notch way off center, I'd send it back to Ruger to correct for free.