well, that is partly true. You could find someone near you with EFILive and for $100 license they could make the changes you want to your truck. The dealer charged me $80 to just change tire sizes from 245 to 265.
But if you need to take your truck to the dealer you will need to find the same person to load you stock tune back in it.
so the next option would be a handheld tuner $300+ then you can load/unload whatever. not too familiar with everything that is available for the LBZ I assume you have and lbz.
so for the LBZ EFILive V2 is $750 which you can do alot with and more everyday.
fill out you sig a little more and were you are located and i bet alot more people will add their thoughts.