The main problem I see is your goal of a stop light street killer. Up to a comp xe268h under 5000 rpm the power band will be similar you might gain 40-50hp up top but with 3.21 your not gonna spend to much time up there especially at street speeds and anything larger is gonna soften the under 2500 rpm making it lazy out of the hole.
Not saying don't swap but stall and lower first gear probably would help a lot especially since you don't want deeper rear gears.
