When you get into the Carter (966, 967 or 2101s) please check the orifice size of the seat (needle and seat assembly). Carter had specs on these and any of the kits bought at your FLAPS will have seats with larger orifices. If memory is correct, .081 inch is the size needed and .102 is what you'll get. You might be able to compensate for this with a lower float setting, but I'd feel better using the right size seat from the start (the larger size will let too much gas into the float bowl before the float can react). On the Rochesters, I really don't know what the proper answer is, and I have not been able to find any data. I have, however found 3 distinctly different sizes of orifice openings. You can see them here:
https://beta.photobucket.com/u/JonGoodman/p/78f73e21-6739-4252-9b4f-1d3c397f77fe
