I am thinking the Carter Thermoquad originally used on 4 barrel applications with a Shaker Hood has a throat diameter that is slightly bigger than a Holley.
I say that because in a few instances where I have used a Holley 4 barrel, as well as a FI Tech (same throat diameter as a Holley 4 barrel), with a shaker setup, both platforms seem to be of a slightly smaller throat diamater, maybe 1/4" or so smaller than a Carter throat diameter.
Is that true?, and if you have the throat diameter measurement for a Carter, that would be helpful