The 216 and 194" Gen-3 use the Rochester "B" with 1-1/2" throttle disc and SAE #2 (small) flange pattern.
194: 1-1/16" venturi
216: 1-7/32" venturi

I also found a larger #2 flange carburetor: 1-9/16" throttle disc, used on some Pontiacs (OHC L6?): 1-5/16" venturi