Wait... we're talking about a 400+ hp BBC? That doesn't require that much of a cam. I'm making almost 400 from a 454 with a 218/224 cam and I run a stock converter in a 4500-lb station wagon.
I think a stall that is slightly above stock should be fine in most cars for a BBC.
Anyway, Rodney... if your main purpose is street and you will see any highway use, pick a gear ratio you can live with. If you post the transmission you'll use and cam specs we can guess on torque peak which means you can predict best cruise RPM on the highway. We can also use torque peak to determine the stall speed and a ratio that will make the best of your launch and acceleration. From there its up to you to pick the ratio that will fit your driving style. For instance if you say you're picking a powerglide with its really high 1.76 first gear, that's a lot different than using a 700r4 with its 3.06 first gear.