Overall very happy with this 1 inch spacer. The fit and finish is good, the price is reasonable, and the necessary hardware and gaskets are included. Remember that the sides and back are undercut on the outside to save weight and material. This is not clearly shown in the drawings. This is not a problem unless you want a very serious gap or "port match" with your distributor. . If you scratch the inner hole aggressively, you can go through the thin sidewalls. I believe this is a RARE issue but…