Cheapest/easiest way to hit 13 flat high 12s?

Ls1 vette stock runs 12s zo6 with slicks run 11s both cars are cheap now ls1 vette ls6 vette go from around 11 to 18 grand stock they both can hit over 180 mph bought mines for actually 11. camaro Ls1 slicks, exhaust, long tube headers,intake, smaller pulley free up some hp, bigger maf sensor, larger throttle body, ls6 intake manifold swap and tune you will be in low 12s with a cam and ported heads maybe 11s in the mids! Mustang cobra 2003 change the supercharger pulley raise the psi and port the supercharger, full exhaust, better intake, and long tube headers and tune with slicks high 11s. My ls1 vette has ported heads by AFR, beehive springs, titanium retainers, 7 degree locks, hardened push-rods by trick flow, and a cam By Comp Cams CC 306 Spec, Long tube headers and full exhaust by slp loud mouth, 45 ib injectors, smaller cranks shaft pulley by BBK, Ls6 intake manifold, 80 mm throttle body by lingenfelter, black wing intake, and a cpu tune by ED wright Texas. Rwhp 464 rwtq 447. So im obviously over 500 hp and tq to the crank also have 125 shot nitrous on my healthy block. Dynod on nitro on mustang dyno 631 hp 601 tq rear wheel, street tires 11.34 slicks and good launch and weather 10,89 car is street legal with real nasty choppy idle.