My #3700 69 RR ran mid to low 12's in the desert with home ported 906's with 2.14 1.81 valves, a 509 cam, 1.75 headers,3.23 gears and a 3500 stall.
The only suspension mods were shocks, subframe connectors and a pinion snubber.
I had a 800 dp and a street dominator intake, timing was set at 36*.

Your car should easily be in the high 12's right now with proper tuning.