This article was written by Chris Teeling.
There were three different versions of the Holley carburetors for 1968 ½ 428CJ Mustangs. Early 1968 ½ carburetors had three steel pins located around the air cleaner mounting boss. Other identifying features are the rounded casting features and a larger reinforcing rib at the base of the center body. Production carburetors dated 833 through at least 854 had these features.
Carburetors produced later in the model run and continuing with the 1969 models had a modified center body casting that replaced the two front pins with ridges cast into the choke horn. Additional modifications included material added to the base of the front bowl vent and two cast in pads between the air cleaner locating ridge and the choke air horn. This version appeared sometime in June of 1968. The earliest* carburetor with this center body style that we have found is dated 864.
The pin located in back of the secondary bowl vent was replaced with a block cast into the bowl vent boss, one of the reinforcing ribs was resized and the center body casting was reshaped to have more angular features.
Carburetors for the "135" series Mustangs did not have the three pins like the early 1968 ½ production carburetors. Detail differences visible on this 7B2 (second week of December 1967) dated C8OF-9510-AA carburetor include straight cut instead of beveled bowl vent tubes, a significantly taller air cleaner locating flange and more rounded venturi casting:
Ford literature from the period (April 1968 Shop Tips) shows what appears to be a modified 1968 Shelby GT500 carburetor(s) on at least one of the early "135" cars. That carburetor had the three pins like the early 1968 ½ production carburetors. Detail differences include straight cut instead of beveled bowl vent tubes, a significantly taller air cleaner locating flange and notches in the flange in front of the choke horn similar to this 1968 GT500 carburetor:
Reproduction carburetors can be identified by the lack of either the locating pins or the ridges on the choke horn. The bowl vent bosses are also different than on either the early or late production carburetors.
* A few of these carburetors have been spotted with date codes of 813 and 814. It is currently believed that these units were actually built sometime after the running change in June.
|C8OF-AA Air Horn Detail||C8OF-AB Air Horn Detail|
Thanks to Pete Disher, Tim Lea, Gilles Marcotte, Chris Simon and Kerry Wortman for supplying pictures and information used in this page.