They work on my car. I have a GT-40 intake with a 1" spacer, deleted my egr (with a 3/4" delete plate), fox throttle body conversion, and those valve covers. It is very close on both sides. The fox throttle bracket is actually rubbing the valve cover and the vacuum lines on the other side are almost touching, but they do work. I just use the cork gaskets for a small block ford and I have never had them leak. I actually have to use a rubber hammer and rag to get them broken loose from the heads.