Well, youre gonna get sh*t from the guys on here for trying to make smoke only... The question should be how do i make more power? Lately, it seems that the diesel community only wants to make their trucks smoke and they dont care about making power, example being people asking how to make smoke switches. Everybody going around blowing smoke is the reason that you are having trouble getting your truck to smoke. The 6.7's now have more emissions equipment than any cummins motor ever before, and that is the reason they are cracking down on emissions. Smoke just looks bad, and in a world turned green, people see it and freak. You never know who youre pissing off by blowing smoke on them... It could be mr congressman or mr EPA who is just going to turn around and vote on stricter emissions laws.
Now as far as making POWER, yes, a larger turbo will help. However its best to match your fueling with your turbo to get best results. The newer trucks give you an opportunity to do some pretty wild things with tuning alone. The first thing i would do if i were you is to do a dpf delete if you havent yet. If youre blowing smoke, youre going to clog your DPF pretty quickly... Along with that you need a tuner that goes along with deleting the dpf. If you would do those 2 things and add an aftermarket turbo you will be very happy with the power results. Remember supporting mods like head studs and transmission/clutch upgrades however. After you start working into that, injectors could be next. Make sure before ANYTHING that you have a set of gauges or a way to monitor your trucks vitals!!!!! The last thing you want to do is burn it up!!!!
Just be careful with throwing around the word SMOKE on this site, its a very touchy subject... Good luck!