Here is a link to my website. The information presented was extracted DIRECTLY from original CARTER prints, not from some vendor with the attitude "what do YOU WANT it to fit":

http://www.thecarburetorshop.com/Carter_YF_Chevrolet.htm

I have found that generally the engineers knew exactly what they were doing.

EDIT: center-to-center bolt spacing on the 966s is 2 15/16 inches.

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop