I dont think many N/A 4G's are running under 13.5 yet ...even fully modified R/T's with:
CAI Intake, 85mm Throttle Body, LT Headers, Exhaust, Cam, a Custom Diablo CMR Tune AND a lighter set of sticky 17" wheels/tires.
BTW, the stock Torque Converter is a piece of crap! Yes even the 2600 in the R/T's.
If you want REAL torque to launch a heavy truck out of the hole you need Two things to get your 60' time down.
A "TRUE" 2800 Stall Torque Converter from Edge, Circle D or ATS
and an awesome set of sticky rear tires, preferably 17" Mickey Thompson Street ET's.
This is the TC I'm going for:
Street Edge - Dodge 45RFE / 545RFE
The low heat, high performance torque converter designed with street use in mind.
The Street Edge
is used in applications with up to 600+ HP and is limited to 2800-3000 rpm of true stall. A good choice for the performance minded daily driver, or weekend racer. A torque converter built efficient enough to drive in the city without adding unwanted heat. Impeller and turbine are furnace brazed. The lock up is upgraded to the latest "high carbon" friction. Hardened input splines, computer balancing and custom configuration. The O.E. stator is upgraded (replaced), and the cover is upgraded to billet steel.