I just finished up the 2013/2014 GT500 definition and figured I better give you guys a heads up.
If you ever dyno one of these cars stock, you will notice the throttle shuts down some. If you swap a pulley and do not touch the tune, the car will dyno exactly the same. The reason for this is the PCM is using a load limit (not used in any other Copperhead that I have seen).
There are two tables that are used to limit the calculated load. One is RPM vs ECT, the other is RPM vs MCT. The hotter the car gets the less load it will be allowed to make, or in other words, it will make less power. Add a pulley and since it would naturally have a higher load, the PCM reacts by shutting the throttle even more, so the boost ends up about the same.
See below:
Another thing about the 13/14 GT500, is that it is setup to use the Driver Demand Engine table exclusively, because the Pedal Pos WOT Start and End are set to the max. So you can either setup the high TP area of the table to account for the new power, or lower the WOP Start and End values. I generally just plug in the values from the earlier GT500s (525 for the start, 571 for the end).