Since your going to the dyno this weekend, your set. The only way to do it right is on a dyno and not just going with what people tell you. Your just going to have to do several pulls to see what you like and what works for your car. There's nothing "random" about it. You make an adjustment, make a pull then look at the chart. How did it effect the powerband? You want that power scooted up or down. It comes down to lot's of pulls and seeing cause and effect.
"If you have good cams but want to move the powerband around a bit, here are some rules of thumb."
"-Retarding both cams will move the powerband up a few hundred RPM. On the EVO with the HKS 272 cams, a popular setup is to use 2 degrees retarded for both cams. Since both cams are moved evenly, the overlap doesn't change, only the lobe centers change, causing the valves to open and close later. In this case, the cams spin half as fast as the crank, so 2 degrees at the cam is 4 degrees at the crank. The crank will be an additional 4 degrees through its rotation before the valves open/close."
"-Advancing the Intake cam, and Retarding the Exhaust cam will open up the overlap a bit. This allows the cylinder to fill sooner due to the intake valve opening sooner, which can sometimes be advantageous in a turbocharged engine. This also helps to improve the idle quality since the Intake cam has a larger impact on the idle than the Exhaust cam does. Or, the exhaust cam can be retarded more than the intake cam, as in a -1 -4 setup. Both cams are retarded in this situation, but the exhaust cam is moved more, increasing the overlap."
"Ultimately this is one of those cases where a dyno comes in real handy. You move the cams around until you find the right combination. Unfortunately theory only gets you so far, and practice makes perfect..."