what cfm carb is this

Found a holley model number 8105b for sale for 75 bucks. Seems like a good deal guy said it came off a running car and looks super clean. Guess the guy went with fuel injection. Im thinking its a 600 vacuum secondary carb . I have a 318 with j heads streetmaster intake and headers. I think it would be perfect for my car. Let me know what you guys think. Mainly wanna know what cfm it is.