Intake tubing sizing

[4OfaKind]

How would you determine the size of intake tubing you would run from intercooler to intake manifold? Is it TB size? If so, how do you determine TB size? Or is it IC outlet size?

400ci LS motor running two 60-1 turbos on a carb manifold w/ intake elbow and LS2 Drive-By-Wire TB

Do I use a 70-ish mm TB , or 90-ish mm TB? How big is too big?
What size intake tube from 2" - 4" or more would be good?

Will drive mainly on the street with some weekend track time.

Thanks

Mal