Fastest car with a stock turbo ran 11.37, dutt neck IC as well. 42 lb inj.
Your use of the word "scanner" concerns me. Is it a scanmaster? In other words how you monitor knock.
I dont see updated fuel pump/hot wire, 160 thermo, and your chip has got to go. And almost forgot valve springs. Get an alky chip from Eric Marshall or an extender from Full Throttle.
Then we have street tires listed and you want consistency..Once you turn the boost up.. those tires are gonna melt.
With a good 60 foot(1.6-1.7), boost in the 22-24 PSI range, running 11:0 air fuel, 23-24 degree timings, car should run low 12's at 108-109. If the motor is weak.. bad tuning.. bad tires.. etc.. cranking the boost may net you zero ET improvement. You will increase MPH tho.
Want 11's.. crank the boost past 25 PSI.. and learn to dial it in. Its been done by many here.
I think you have some stuff to do before you jump into cranking up the boost with alky. Running higher boost will yield a noticable improvement seat of the pants. And yes it will pickup more at the track.
A lot of variables with a car thats 20 years old. Hope I covered the basics. There is no majic wand.. you need to work your way up..