Milling the choke horn off a Holley without doing any other mods probably will not gain anything. The old Carb Shop modified the 3310 on my Falcon by removing the choke horn and adding 4 corner idle and other mods which was good for a .50 reduction in the 1/4.

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\'58 Morris Minor 289 S/S MM
\'62 Falcon 351W \"Just Falcon Around\"
\'72 Datsun 240Z 302/C4 Junk Yard Refugee