The Holley float bowl vents stick straight up out of the carburetor body and vent directly into the air cleaner. If you want to do it correctly, put a nipple on the air cleaner base and attach the charcoal canister connection that would go to the float bowl vent there. Although it will "somewhat" work, the only way it will work 100% is if you use a different carburetor with a dedicated bowl vent off to the side. Otherwise most of the vapors will simply escape the air cleaner. The Thermoquad has one such dedicated float bowl vent. You "COULD" attach a Y hose to each float bowl vent on the Holley, drill a hole in the base plate of the air cleaner, put a grommet in it to seal it, run the hose through there and to the charcoal canister. Then you would have it working correctly.
