addco 751 sway bar for 1963 Dart

I am considering ordering this bar for my 63 Dart. Question I have is do the aftermarket bars require you to drill the K frame to mount the brackets or are there existing holes that they utilize? I haven't crawled under my car to look yet, but don't remember seeing any extra holes when I cleaned and repainted it.

Do they make a huge difference on handling? I took my car around the block for the first time yesterday and noticed it does seem to have body roll going around corners more than I'm used to. All the suspension is new, so I know it's not worn parts and from what I've read these cars do tend to like to "dip" when going around corners.