Really cant be done like they are talking about since we dont have a distributer cap like they do. Old vehicles with distrbuter caps we often did this too, slightly increase the timing and slightly gap the plugs higher and you got a slight more seat of the pants power.
Modern distributerless systems this cannot be done too b/c its computer controlled. What can be done is a reprogrammer such as the jet, unichip, etc kinda thing. This messes with the timing slightly but nowhere near as much as you could ever do with a plain old cap and rotor.
Ex: Friend of mine had an 88 Camaro with the 305 and a stick, we increased the timing about 3-5 degrees (I forget exactly) after swapping to the wires, plugs, etc to aftermarket race style MSD stuff and he got a noticeable gain but a more loopy idle and mpg went down.
If you want MPG, downsize the tires, disconnect the front driveshaft if 4wd and drive like grandma-i bet you get 18mpg.
