Best Gears for a 408 Stroker?

Mopar put 3.23s in a lot of high performance cars. That's cause it is an excellent compromise gear. (That's also why 2.94s and 2.76s are hard to find. NOT intended for performance). A 4000 converter with 3.23s will leave harder than a 3.73 with a 2500. A GOOD 3500 will drive like a stocker.
Mind if I ask a question? If economy and freeway flying is important, why build a 408? Sounds like a 318 would suit.