I found some differences in components in the fast idle mechanical components. Here are some photos.
1 The fast idle circuit used on a 4100 (2100 carburetors use some of the same components), a C5ZF-E (date unknown).
2 Another view with two arrows to the cam on the left, the center arrow to the rod, the right arrow to the lever.
Ref 75 MPC Illustration Sect 95, page 4, cam identified as 9597, rod identified as 9D530, lever as 9F577. (see below)
3 Two cams.
4 As above.
5 As above. These are metal stamped "H" and "C", the one on top is from a C4GF-AF carburetor used on 64 Mustangs (the "H"). I don't know the application of the lower one (the "C"). The cam referenced in pics 1 and 2 on the carburetor is marked "A".
6 The lever. C4AZ-9F577-A with screw 372307-S(
, 6-32X3/4 hex drive.
7 As above.
8 Three rods. The one on the right should be C4AZ-9D530-A, the other two are used after 1/15/65, the one on the left should be C3AZ-9D530-A but I am not sure and the center one seems to be a compromise in design, the longer "shaft" on the bottom is like the rod on the right, the top is like the one on the left. The left and center ones use two 351825-S(2) "C" clips, one on the right uses one. Note the deformed tabs on all for proper depth control. T the one on the right uses an "ear" to fit the key hole slot in the lever.
This is presented to show differences in 4100 external components.
Jim
I think the part number for the cam is C4GY-9597-A and per the MPC is unique to 64 Mustangs (and earlier Fords). The cam in picture 1 and 2, the assembly may be C5AZ-9597-D, the
