What should i change to get into high 11's?

So I would like to build a mid to high 11 second car out of my current 12.9 car. I am of course trying to do this right the first time and still want to be able to hit the freeway and cruise since this is a more of a cruiser than a racer. The reason I have this specific goal is to whoop my brothers 383 nova that he got on the road. His car theoretically runs low to mid 11's and the motor dyno'd 520hp 505 tq. I am wondering if I should go 408, buy a converter from dynamic and that would do it. Any and all similar builds and advice are appreciated. No nitrous! I currently have this set up.
69 dart all steel full interior
360 10:1 compression
X heads with port work 2.05 1.62 valves
Comp flat tappet Hyd. Xe284 .507/5.11 lift 1.5 ratio
Edelbrock air gap
750cfm demon carb
Tti exhaust/ 2.5 pipe
Msd everything
3.55 locker
2500rpm b&m torque converter on. 26 inch tire w/ ss springs
Do not know hp or tq figures. 60ft times were 2.1's