well guys i took off my small pulley (2.75) and currently have the 3.1pulley, right now im running 9#s of boost and 18*'s of timing and with the 2.75pulley was running 13#s of boost and 12*'s of timing, ok now i want to down size the pulley enough to be in the 12's, running a 13.1@103mph so almost there, how good is a 2.9 or 3.0 difference,