Yes, I use this spacer. The inventor of this spacer is no longer with us as he passed away in May of this year. His name is Thomas "Corky" Capoferi Sr. of Corky's Competition fame. I was one of the first racers to use this spacer in the late 70's and it was developed over time into it's current form. The reason it looks like this now it that you can use single hole spacers to increase the plenum area for fine tuning of the air fuel flow at the bottom of the manifold preventing fuel separation in the air stream.