Bought these for my 2" spacers. They're barely enough. I couldn't fully tighten the bolts in the manifold. If I can find extra carburetor gaskets or use a basket maker, they might last a long time. It's definitely about to long to make a 1" spacer. The 2" spacer is slightly missing. So not sure if there is any real purpose. They should be at least 1/4 inch longer.