If the idle is crap then its not the spark plugs causing that unless the plugs are bad. The gap needs to be closed up at higher boost because of the cylinder pressures involved. You don't see that pressure at idle.
just to update found the hard vacuum line that goes to the gauge dry rotted and cracked, replaced the section and now vacuum doesnt go below 17 in park. got a small leak somewhere else .. ill find it
I have seen boost up to around 25lbs after my most recent pulley adjustment since the shootout and running the 103's at 35. I dont see a need in such a dramatic decrease in gap for just a 10% pulley.