Best Gears for a 408 Stroker?

Mind if I ask a question? If economy and freeway flying is important, why build a 408? Sounds like a 318 would suit.
i don't understand why people leave gearing and stall as an afterthought, a 408 with 3.73 will have similar torque to the ground as a 512 with 2.94 gear, on a street car most will self impose a gear and stall limitation, just build for it not against it. With all these displacement and power adder options easy to build lot of hp at street speed rpm. 1500-4500 rpm.