for 1970:
all the T/A & AAR Six Pack center carburetors are 50 state with a bowl vent

the CA emission (N95) 440 Six Pack center carburetors have a bowl vent (w/3 nipple valve cover breather)
the 49 state 440 Six Pack center carburetor DOES NOT have a bowl vent (w/1 nipple valve cover breather)

for decades the only 440+6 center carburetors available new have been the CA emission units with a bowl vent