The SCT is a device that can rewrite tunes to the PCM. It can store 3 custom tunes and the original stock tune. It is married to the truck by the VIN. Torrie has a number of "canned" tunes. They are realitively safe! Call him and he can direct you to which canned tune will work for you. Dyno sheets can be sent to him via email, he can then adjust the tune for your conditions. He will email the new tune to you so you can upload it to the SCT and then upload to the PCM. The shop with the dyno may have the SCT software and a competent tuner . There are no adjustments you ,yourself can do with the tuner. just load or unload tunes. When you sell the truck, the SCT tuner should go with it . if not, you will need to replace the stock tune to the truck to unlock it or it will be useless to you for any other vehicle.