Look, I have a 4200 lb 300c with a stock 5.7 Hemi and a bolt on remote turbo, and on stock tires, I have pulled a 4.18 second 0-60.

Getting an SRT6 under 4 seconds is more of a traction problem than a performance mod problem. Do the simple performance mods, then work on the traction issues where you can use that power.