[Dan Case]

Most Cobras with 1-4V (several Ford 4100-A models between prototypes and C4OF-AT or optional Holley® 4V) or 2-4V (mid-September 1963 and later option) used automatic chokes operated by hot air pulled from the outside of one exhaust header.

Cobras that received engines manufactured between about the third week of May 1964 and the end of July 1964 received manual choke carburetors (Ford 4100-A C4OF-AL).

About the sixtyish very late Cobras cars completed after August 1964 received a manual choke model 1-4V system (Ford 4100-A C4OF-AL w/manual transmissions & Ford 4100-A C4OF-AT w/High Performance C4 automatic transmissions) or the previous 2-4V system with automatic choke. For the late cars with manual choke the knob placement was not consistent. There were a couple of common locations. The best source of period photographs is magazine articles covering new car road tests 1963-64.

Two (2) street Cobras and one (1) Cobra sold as a Stage I Competition car were delivered with some version of early 1965 MUSTANG GT350 carburetor during the year 1965. (I had the R-3259A carburetor, dated 4B5, from CSX2555 for two decades. It was manufactured in the second of the two weeks R-3259A models were produced in December 1964 at the first design level of carburetors were made in. The first two production runs of units (R-3259A design level) were essentially R-2668 assemblies with different fuel bowl assemblies, manual choke, and an external fuel transfer tube system. The original unrestored very nice condition R-3259A factory installed on CSX2555 by Shelby’s works was sold to the owner of 1965 MUSTANG GT350 SFM5026 in 2007.)