Dawson Precision makes replacement pinned front sights of varying height and width. S&W, per my call to them, only makes one front sight. I had a 'smith install the one I bought for my 686 5", works great.

http://www.dawsonprecision.com/

As of a few years ago, S&W offered several different styles and heights of front sight blade. I replaced the red ramp on a couple of revolvers with a black partridge sight. As was mentioned drill from each side.

I need to get a replacement front and rear for a 317. It has the V rear with Hi Viz front, and I just can't get repeatable longer range accuracy out of them.