Rofl. If you can even make it to 160 on that 5.7l HEMI your drive shaft is going to make you pay for it. And no, they are not like Harleys, a tiny tune and a CAI and exhaust and a TB isn't going to make yours destroy a 6.4l. Good luck thinking you are better than those with the 6.4l though...that "dead weight" is what, 40lbs? Seriously though that old 5.7l truck motor ain't gonna touch a 6.4l HEMI unless the driver does not care. Remember you are kinda driving a yacht with two doors, but no, just no on the 5.7 vs a 6.4l, esp with "bolt ons"Took my 2011 RT 5.7; installed cat back exhaust, CAI, 85mm throttle body (90 would have required porting the intake manifold), and tuned with a Diablo T1000 to 93 octane. With the Diablo you can override the 160 MPH Speed limiter (set mine to 190) as well as increase your rev limiter from the 5500 stock set (set mine a couple hundred above red line), and increased throttle responsiveness by 10%. The Diablo Tuner is freaking awesome! I'm old school - 53 years old....still remember advancing or retarding the distributor and messing with points. Now it's all touch screen electronics with instantaneous results. Would you believe my fuel MPH has improved? The ENGINE is breathing like it was designed to do. They are like Harleys......you get it stock and you build the shit out of it. By removing the stock exhaust you will drop the dead weight from the baffle boxes and smaller mufflers. All those items above are all easy bolt on added HP. I've not out it on a dyno, but trust me, this thing would give any stock SRT8 a run for it's money now....especially with me driving....lol.