340 carburetor size?

Hello,
What size single four barrel carburetor was installed on a 1971 340 engine. It is a factory stock engine with a 727 automatic transmission. The VIN# says it's a high performance engine but I think they were all the same, a sales gimmick? Anyways, would the four barrel carb be a 600, 650, 750cfm? What was the stock sized cfm carburetor installed on these engines when new?

Thanks for your help,

Tirekickertoo