2015 RT 5.7 M6
Have a 2013 5.7 overland myself and used HP tuners to tweak the PCM (BTW the WOT is delayed by several seconds on these engines in the stock tune)...wife won't let me tweak the TCM. Definitely woke it up but now must run premium. Not sure how many miles you have on yours but mine is at 120Kmiles and I just discovered my passenger side engine mount is shot...motor moves a couple of inches when you stab the gas in gear (apparently a common problem). There is also a noticeable thump when doing this from a dead stop. Just giving you a heads up.I had a '16 SRT392 manual that sounded awesome. Unfortunately, I had to sell it in late 2017 to balance out some financial considerations (new, to us, house with all of the extra expenses). I've been missing the rumble and fun of driving the SRT392 so I opted to mod my '12 Jeep Grand Cherokee Laredo 4X4 5.7L. I added a Corsa CAI, Corsa Sport exhaust system professionally installed, Performance Chip and Pedal Commander. All for just under $2,600. Much cheaper than buying another toy and it sounds great and is much more fun to drive. I've also retained the convenience of keeping the utility my Jeep. A win-win all the way around but I do miss the Challenger Talk Forum.
Here are some pics.