1966 Corvette: Service Bulletin: Engine Surge - 1966 427ci Corvettes with Holley Carburetor
Model Year: 1966
Subject: Engine Surge - 1966 427" Corvettes with Holley Carburetor
Source: Chevrolet Technical Service Department - Field Service Engineering - 02-15-1966
Early 1966 Corvettes, equipped with the 427" engine with Holley carburetor, may experience engine surge during light to medium acceleration between 40 and 60 MPH. No. 63 main metering jets as used on these early units tend to be too lean.
Carburetors with build code date 594 or later incorporate #65 main metering jets and are satisfactory. The build code date is stamped below the Chevrolet part number located on the carburetor air horn. The first digit is the year, the second is the month, and the third digit is the week of the month.
To satisfy field complaints, replace the #63 main metering jets with #65 jets, Part No. 2193938.