The standard Edelbrock performer is a spread bore intake. There's no need for that 1" spacer. They are almost always a point of contention for vacuum leaks. This is all you need.
Edelbrock 2732 Edelbrock Carburetor Adapters | Summit Racing
It seals around the outside of the secondary barrels properly. That may or may not be the issue you have, but I sure wouldn't be running a spacer like that when it's not needed.