You might want to call Jon on that question. The metering rod you have will work, however...I have a note that says the metering rod marked 75-952 was used in the 2101S (YF for the 235 with auto choke). That note also tells me the 75-837 was used in the YF965S (YF for the 216, 1937-1952 Chevy and 1953 Chevy truck 216). The 965S was like yours but with auto choke.
The note I have says the measurement for the 75-837 rod should have been: economy step--.074" diameter, middle step tapers to .058" diameter and power step is .047" diameter.
The 75-952 rod on the other hand is .068 economy step, .060 midrange and .050 power step. The main jet in the 2101S was .0945" and in the 965S the main metering jet was .098".
So with a main jet of .098 and using the 75-952 metering rod it looks like you'll be running richer in town than you should (due to the smaller diameter of the economy step) and leaner at midrange speeds and in power mode (due to larger diameter of midrange and power steps on the 235 rod).
As I said, I'd ask Jon H. There is a notable difference in the size of the main jet here and also there's a notable difference between .074" and .068". My guess is some rebuilder swapped parts here. Good luck!
