Choosing a DCOE Carburator

So I have been reading my book on tuning DCOE setups, and a couple of websites.

So the best I can tell I will need 42mm or 44mm chokes, and the best I can tell I would need either a 48mm DCOE or a 50mm DCO/SP. There is also a 55mm DCO/SP carburator, but I cannot find much on available venturis for the 55mm carb.

Some places say that the barrell should be 1.25 x choke, or 52.5 to 55mm. Others say choke + 7 = 49 to 51mm.

I can easily get 42-46mm chokes for the DCOE 48mm carbs. The other benefit of the DCOE over the DCO/SP is the idle bypass circuit, which is supposed to do good things for idling and not fouling plugs. So I could stick to the 48mm DCOE and they are about $20 cheaper a carb.

Other thoughts?

Size depends on the airflow through them. Having the same ci turn at say 4000 and 7000 rpm is a world of difference in airflow demand...Since you don't have a plenum, getting the size of them right is critical for drivability and performance, certainly with carbs that depend on vacuum to get a signal in the venturi. Because you have one bore per cilinder it's easy to disrupt the vacuum signal.

Not that I can tell you what size you need, I just give you the info I got when I choose my setup.

the 42mm choke supposedly support 480hp, 44mm supposedly 530hp. The Des Hammill book says that a 43mm choke is necessary for 800cc cylinder. A 396ci small block has a cylinder of 809cc. I lean towards 42mm, and a 48mm DCOE with the bypass.

Also IDF carbs are about $100 cheaper than a DCOE.

Manifolds costs the same. Although the DCOE manifolds have much longer and straighter runner.

IDF's will not fit under the hood of a vette.

Well that answers that.