Hi Bill, I was talking to a fella the other day and the subject of 4100s came up and some of what he said confused me. I went along with him all the while knowing that I would ask you for the "straight skinny"; To wit: I thought that 4100s with the stamping C4GF were designed for Comets with the 289. He says that the C4GF is only a service number and showed me a 1.08 carb with the C4GF on the foot and a C5ZZ designation on the Tag! He swears that this particular carb came on a 65 Mustang that he once owned. If this is true then what about 1.08s with the C4OF or C4DF designation? As always thanks in advance for your help

Kind Regards Tom

So you are right, C4GF is from a 1964 comet with the 289, however remember that those early mustangs often robbed parts from many of the small car lines, comet, fairlane and most especially falcon since the mustang was originally a falcon car derivitive.

So it is concievable and I have seen cases just like you are describing where a 64 modle part or carburetor has been "obtained" and then a new tag has been added to reflect the new application.

From a operation standpoint a 64 comet with a 289 is practically the same as the 65 mustang with the same 289 engine, in fact if you looked closely it was probably an early 65 model and the WHOLE engine probably came from the comet line.

Not sure of the differences between the C4GF and the C5ZF carbs but it was probably very minor, if anything other than the application. Willing to bet the choke assembly was the only thing different since the 64 had some slight differences.

Bill White
White Automotive