Reply to "Extra Horses"

4 hole spacers often make small improvments in air flow through a carb because they extend the downstream side of the "venturi" before it suddenly transitions to an open plenum, and all the "pulses" occuring in the plenum. Open spacers are used to adjust the volume of open plenum intake mainfolds, often resulting in additional high rpm power, sometimes at the expense of throttle response. It's always good to have a bit of a non metal spacer between carb & manifold as a heat insulator.

But the true effectiveness of the spacer in your picture will only be determined on a dyno or at least with a stop watch, I never trust the "seat of the pants" stuff. Or advertising.

Caveat Emptor.

Your latin friend on the DTBB, George