Converter/how much stall?

hi all.....
having gone to the Vortech from NA I must say the results are impressive. Ran mid 14's on the 1/4 NA and PB of 11.67 with the supercharger. Same engine, trans, gears.
Off the line she seems a bit sluggish to the sixty foot and then off like a scolded cat. Rear gears are 3.5:1, 26" hoosier qtp, stock 11" converter has been loosened up as much as possible. Just wondering how much stall is too much for a street driven car. Boost seems to come in around 3000. Would I gain from more stall to get off the line better. Guys that did the verter said about 2200-2400.
Had the same issue with the 383 in same car. Got a 3000 stall verter and the car was so much quicker off the line and improved ET's.
combo is...
360 -9:1 cr
727 - transgo tf3 kit
Vortech V2, 2.87 pulley, 7" crank pulley
ProSystems blo through carby
3.5:1 gears
26" hoosier QTP tires
car weighs 1650KG with me in her

any help here much appreciated. Cheers