Still scratching your head on this?
If you're really set on a double pumper for street, then a Holley 600 or 650 rated 4150 is your best choice. Especially true with stock or stockish converter and those gears.
A higher rated carb has potential for better 1/4 mile performance with the right converter, tires, gearing.

Since you have unknowns, I agree with those recommending a vacuum secondary carb. Only dings against the T-quads is that you will have to buy used, and the rear bores may not clear the Eddy RPM. My suggestion is to try the new Speed Demon instead as its a more square bore interface with the intake. It's also a lot cheaper than that shiny "street HP".