I went for the one inch spacer initially because I have the Airgap designed for the Q Jet which does not have the divider milled down.
The milled divider lets the motor get fuel from all four barrels of the carb,
when I had the four hole spacer each side was feeding off only two barrels,
didīnt idle well or accelerate smoothly.
Comparing my original one inch four hole spacer setup to my two inch open, itīs a world of difference car pulls much harder right off go.