The "common" Weber is the Ford Pinto model, which has 32 & 36mm throttle discs with 26 & 27mm venturis (the Chevette and 1978-* are smaller).
It's about 270 CFM @ 3.0 Hg", slightly smaller then the Rochester "small" 2G at 280. The original 261 Model B (1-11/16" throttle disc, 1-15/32" venturi) is smaller at about 240 CFM (and the 235 even smaller at 200). If the carburetor were too small, the WOT vacuum would increase and the CFM as well.
Since the secondary linkage is mechanical, it will go to WOT whenever you floor it (no vacuum linkage).
