Need advice racing a 380 horse crate engine

Your car may not have as much power as you expected... from the numbers you posted, that would mean about 225-250 HP.
My buddy has a Cutlass that weighs about 3600 pounds. The car dynoed at 400 RWHP. He has a 3600 rpm stall converter. His car runs pretty consistently in the mid to high 12's at a bit over 100 mph. A higher stall converter would very likely help your times, and launch the car harder.
Half the fun is chipping away at the ET, play around with it and just have fun!