Just to summerize the mods you've done that might really impact performance:
10% pulley
255lph Fuel Pump
Removed Silencer
Cold air Intake 9" filter
Aluminum Driveshaft
Aluminum Flywheel
Lightened Clutch
2.5-3-2.5 manifold back exhaust
With 220hp/325 torque you can look at the top SC list and see how your numbers compare to those that have 1/4 mile times.
With the opened intake and exhuast with the 10% pulley, that's probably about the right numbers to expect. Those lighter driveline components certainly also play a big role.
If you have the money, get the Griffin aluminum radiator. Otherwise just get your stocker re-cored with a 4 row core. Stock is 2 rows. Then wire the low speed fan to be on all the time.
But the biggest thing impacting your run after run slow down is going to be SC outlet temps. You are pushing more air through the SC which is inceasing outlet temps. Your stock Intercooler isn't sufficient to decrease outlet temps consistantly as it heats up. This happens with just the stock pulley, but with your underesized unit it gets even hotter. Short term a double intecooler core with a fan might help, but long term, you'll want a front mount intercooler.