Brads1951,
One choke connected (rear one) worked fine for me. You might want to consider somehow "tying"/holding the unused choke valve/flapper open but leaving the parts in place.
I dimly recall reading here that removing the valve/flapper parts somehow affects air flow.
Let's see if someone who knows carburetors clarifies/corrects this.
What size engines did the two Rochesters come from?