What threading is the top barrel?

What size Holley 2 barrel carb?

• I have a 383 Stroker engine with fast burn vortec heads 427 HP 468 ft lb.s torque and I want to put a Holley 2 barrel car on it. I have seen some SBC built similar that have 800 cfm 4 barrel edelbrock carburetor but haven't seen any Holley 2 barrel carbs with that high of cfm except a couple years ago seen a 890 cfm holley 2 barrel, not thinking I will see one of those again soon but see some holley 2 barrel that are like 350 cfm 500 cfm 600 cfm I think and once in a while a 650 cfm. What size holley 2 barrel do I need be on the look out for, and any ideas about how I can modify it when I get one and or can I change size of excelerator jets what have you. Sense going from a 4 barrel say 800 cfm to a holley 2 barrel do I need higher cfm or lower cfm or how does that work out or maybe the question is does the cfm need be up or down sense going from 4 barrel to 2 barrel. A long time ago I had a SBC that had a 2 barrel on it and don't know the size it was but it sure worked good and when accelerating it had huge streams of gas flow, it was definately modified and would like to come up with something like that. We don't have that kind of fuel as back in them days and plan to use just pump gas and the car is going to have a 4 speed automatic and a 3.73 or a 3.08 gear ratio rear end, any ideas will be helpful. Thank You!

• Answer:

  If you are trying to duplicate what you have "a long time ago", I probably wouldn't start with a 427HP stroker. A 2 BBL is not likly going to bring out it's potential unless you have 3 of them. A 770CFM Street Avenger w/ electric choke would be one I would look at. However, if you are after a 2 BBL, I haven't seen anything readily available over 500, but they can be rejetted.