Originally Posted by coyotekiller
Are you talking about set tunes from a dealer or something I have to come up with?
The SCT is a programmer that plugs into the OBDII port. It pulls out the factory programming and replaces it with a performance program. There are different SCT models to go with. The Livewire and TSX have a large display for gauge read out.
Custom tunes are written by Authorized SCT vendors. This will allow you to have the truck perform how you want it to (racing, street tunes, towing,ect.) They can adjust when you would like the torque converter to lock, if you want to use the VGT to close to act like a Jake brake for towing, if you run larger injectors, turbo,ect.
If you buy a new unit, the TSX, Livewire, SF3 will have canned tunes (SCT universal tunes), and also let you use custom tunes. The X3 will only use custom tunes.
Most members go with the X3 with the EDGE Insight CS or CTS for gauges. This will monitor every sensor on the truck except fuel psi and EGT, you will need separate gauges for them.
You can check out the vendor section to find these products, some even sell the SCT with custom tunes in a package deal.