School me on torque/stall converters

Like the article said - your best overall convertor will be "locked" (meaning above it's stall speed) at the highway cruise rpm. I find 22-2500 is pretty good, because there's enough slip in first, but on the highway it's revving higher than the stall speed. BTW - mileage is more about matching parts. A friend of mine gets over 17mpg in a heavy E body w/3.23s and a 460hp 422. His convertor (727) is 2200.