When using a edelbrock carb w/a performer intake you MUST use a 1/8" spacer & 2 gaskets.(look at Summits cat). If you have a heat problem in the engine problem a wood/plastic/or metal spacer will give limited help. Yoy need to made a way for more air to get out of the enine compartment.
This spacer is needed when a square bore carb is placed on a spread bore intake for clearance.........Don