Cliff's Quadrajet Parts and Rebuild Kits
General Category => Quadrajet Carb Talk and Tips => Topic started by: Cadman-iac on November 07, 2025, 11:43:32 AM
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Cliff suggests in his book that you might want to move the discharge ports, (secondary accelerator nozzles), to under the air valve.
I was just looking at some air horns and the ports are aiming slightly upward, probably because of the location and the drilling methods used.
If you redrill them below the air valve, you almost have to do so with a downward angle, again, because of drill bit length and the size of your drill.
Will this change how they work, or does it really matter as long as they're in the correct location?
And which is more effective, relocating the holes, or notching the air valves?
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I relocated mine under the flaps and they are facing down. I don't think up or down matters much. I've never done back-to-back notched flaps vs relocated under the flaps testing.
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They will work fine under the flaps at any angle. Solid flaps with holes under them is the best set-up as it pulls fuel sooner than other set-ups. Some factory HP carbs came with this set-up, others used "cut-outs" and some had large openings directly in line with the flaps to expose part of them to the underside (1975-79 Pontiac 350, 400 and 455 carbs).....