Should I Run A Carb Spacer?!

Mount the carb directly to the manifold or run a spacer?

Open bore/plenum? Best for single plane manifold?

4 hole?

What material and what thickness?

I have a Weiand 7512 Xcellerator (open plenum / single plane......right?)

Will I need any new carb brackets or linkage issues?

Thanks for any and all info!!