What Will It Take....

dang bro you going to need a ton of cash into your car if thats all the mods you got on so far! get some heads,headers,pulleys,intake,cams..... hell all that costs less then a supercharger lol.... thats should get you to low 13's
 
I'm running 275 width NT 555r Drag Radials with much the same mods as you, except 3.73s, off road x-pipe and headers. I'm in the LOW 13s, 13.1/13.2s.

Softer rear shocks/springs and you're there.

S