It really depends. If the radius is not overly severe, you can do it with a spacer. Spacers are cheap; pads somewhat more pricey. If that length works out about right, that would be the way to do it. Figure out where your holes in the stock need to be. Boil the spacer for about 2-3 minutes, lay it where it will end up and place some weight on it; shot bags work well. it should end up fitting properly. Then you need to flatten the back side of the spacer to receive the pad. Freeze the spacer and belt sand it quickly. Put it back in the freezer every few minutes until you get it right (flat). Now you have a flat surface to receive the pad. It takes a little more time but please don't cut the stock!
